diff --git a/adapterguide/index.html b/adapterguide/index.html index eed32eb..ea8b318 100644 --- a/adapterguide/index.html +++ b/adapterguide/index.html @@ -19,17 +19,20 @@ - Glenwing's Guide to Display Cables / Adapters (v2) - + + Display Cables and Adapters Guide + + +
- + @@ -1413,7 +1420,7 @@ While it is tempting to call High Speed HDMI cables "HDMI 1.4 cables", Premium High Speed cables "HDMI 2.0 cables", and 48G cables "HDMI 2.1 cables" because the ratings of those cables match the maximum bandwidth limits set by those HDMI versions, this should be avoided for the reasons explained above. HDMI versions define more than just bandwidth limits, and calling a High Speed HDMI cable an "HDMI 1.4 cable" implies that it is necessary in order to use HDMI 1.4 features, but this is not the case. You only need it to use the 10.2 Gbit/s bandwidth introduced by HDMI 1.3/1.4, not for the other features. For this reason HDMI cables are simply rated by bandwidth, not by "HDMI version".

- Also note that the certifications do not actually tell you anything about the maximum bandwidth of the cable, except that it is at least the listed amount. A High Speed certification simply means the cable was tested at 10.2 Gbit/s and functioned properly at that speed. The maximum bandwidth that the cable can handle could actually be anything above that, be it 10.3 Gbit/s, 20 Gbit/s, or 100 Gbit/s. Of course, you might think "if it could handle all the way up to the next tier of certification, it would just be rated at that tier instead!"; well, yes you'd think so, but unfortunately that isn't always the case, as explained in the next section.

+ Also note that the certifications do not actually tell you anything about the maximum bandwidth of the cable, except that it is at least the listed amount. A High Speed certification simply means the cable was tested at 10.2 Gbit/s and functioned properly at that speed. The maximum bandwidth that the cable can handle could actually be anything above that, be it 10.3 Gbit/s, 20 Gbit/s, or 100 Gbit/s. Of course, you might think "if it could handle all the way up to the next tier of certification, it would just be rated at that tier instead!"; well yes, you'd think so, but unfortunately that isn't always the case, as we'll see below.

High Speed HDMI Cables and HDMI 2.0

@@ -1427,11 +1434,15 @@
  • Category 2 ("High Speed") HDMI cables, which are tested to work at up to 10.2 Gbit/s
    • - The Premium High Speed HDMI certification did not exist at that time. Contrary to what some people believe, the HDMI 2.0 specification does not contain any kind of "HDMI 2.0 compliance test" for cables. No changes to the cable testing procedures or the requirements for passing the certification were made compared to HDMI 1.3/1.4.

    + The Premium High Speed HDMI certification did not exist at that time. Contrary to what some people believe, the HDMI 2.0 specification does not contain any kind of "HDMI 2.0 compliance test" for cables. No changes were made to the cable testing procedures or to the requirements for passing the certification compared to HDMI 1.3/1.4.

    - For the next two years following the release of HDMI 2.0, the HDMI Consortium insisted that cables which had passed the High Speed certification would be sufficient for the increased 18.0 Gbit/s bandwidth introduced in HDMI 2.0, and no higher levels of certification were introduced. During this time, a vast number of HDMI cables were manufactured which were capable of handling full HDMI 2.0 bandwidth (18.0 Gbit/s), but only received a High-Speed certification, the highest certification available at the time. Due to this, there are a large number of High Speed HDMI cables which do work at full 18.0 Gbit/s HDMI 2.0 bandwidth, despite not having the Premium High Speed certification. Most of these cables were never resubmitted for certification under the new certification tier once it was released, or if they were, they were sold again as a different product.

    + For the next two years following the release of HDMI 2.0, the HDMI Consortium insisted that cables which had passed the High Speed certification would be sufficient for the increased 18.0 Gbit/s bandwidth introduced in HDMI 2.0, and no higher levels of certification were introduced. For the most part, this turned out to be true, and many High-Speed HDMI cables (even ones that had been manufactured before HDMI 2.0 existed) did function with the increased bandwidth. Official statements from the HDMI Consortium together with many real-world examples combined to create a very solid belief that any certified High-Speed cable could handle HDMI 2.0 bandwidth, which is why many people still maintain that position to this day.

    + + While it is true most of the time, it turns out not all High-Speed cables will work at the full 18.0 Gbit/s bandwidth, even if they have a valid High-Speed certification (not to mention the countless counterfeit non-certified cables on the market that are sold as "High-Speed"). This is particularly true with longer cables, in the 10–15 meter range (30–45 ft.). While they may be compliant with the High-Speed certification requirements, the majority of these cables will not work at full HDMI 2.0 bandwidth.

    + + Meanwhile during these two years, a vast number of HDMI cables were manufactured in the knowledge of HDMI 2.0, including longer cables which were capable of handling full HDMI 2.0 bandwidth (18.0 Gbit/s), but only received a High-Speed certification — the highest certification available at the time — despite being more capable than other longer cables already on the market. Due to this, there are many High Speed HDMI cables which do work at full 18.0 Gbit/s HDMI 2.0 bandwidth, despite not having the Premium High Speed certification. Most of these cables were never resubmitted for certification under the new tier once it was released, or were simply sold as a different product if they were.

    - Many existing High Speed HDMI cables (manufactured long before HDMI 2.0) also worked fine with the increased data rates, but despite the HDMI Consortium's initial claims not all certified High Speed HDMI cables could handle it. Finally, after numerous complaints and reports during the two years following the release of HDMI 2.0, the HDMI Consortium revised their position on the matter and released a third cable certification tier, Premium High Speed HDMI, which actually tests cables for proper operation at 18.0 Gbit/s.

    + The failure of some High Speed cables at higher bandwidths was problematic for some though, and did not go unnoticed. Finally after numerous complaints and reports, the HDMI Consortium revised their position on the matter and released a third cable certification tier two years after the release of HDMI 2.0 called "Premium High Speed", which actually tests cables for proper operation at 18.0 Gbit/s.

    HDMI Licensing acknowledges the issue of some "high speed" cable not quite being up to the task of actually handling the full 2.0 bandwidth, saying:

    @@ -1439,7 +1450,7 @@ "Although many current High Speed HDMI Cables in the market will perform as originally expected (and support 18Gbps), some unanticipated technical characteristics of some compliant High Speed HDMI Cables that affect performance at higher speeds have been found. These cables are compliant with the Category 2 HDMI Cable requirements and perform successfully at 10.2Gbps, but may fail at 18 Gbps."

    - So while many High Speed HDMI cables will handle the full 18.0 Gbit/s bandwidth of HDMI 2.0, it is not guaranteed, while a "Premium High Speed" HDMI cable has been tested to definitely work.

    + So while many High Speed HDMI cables will handle the full 18.0 Gbit/s bandwidth of HDMI 2.0, it is not guaranteed, while a Premium High Speed HDMI cable has been tested to definitely work. If you're buying a new HDMI 2.0 device like a 4K TV and you have some High Speed HDMI cables already, you may not need to replace them; you should check to see if they work before buying a new HDMI cable. If you are buying a new HDMI cable though, you should look for a Premium High Speed cable.

    For a more in-depth explanations, I recommend reading these articles:
    http://www.bluejeanscable.com/articles/note-about-hdmi-2.htm
    @@ -1450,11 +1461,12 @@ Is HDMI limited to 60 Hz?

    - No, it is not. No version of HDMI has ever been limited to 60 Hz. Even HDMI 1.0 was capable of supporting 120 Hz at lower resolutions like 720p. HDMI 1.3 added enough bandwidth to handle 144 Hz at 1080p, and HDMI 2.0 added enough to handle 144 Hz at 1440p.

    + No, HDMI is not limited to 60 Hz. This has never been the case, with any version of HDMI. Even HDMI 1.0 was capable of supporting 120 Hz, at lower resolutions like 720p. HDMI 1.3 added enough bandwidth to handle 144 Hz at 1080p, and HDMI 2.0 added enough to handle 144 Hz at 1440p.

    Some 120+ Hz 1080p monitors will not accept signals above 60 Hz over HDMI (such as the ASUS VG248QE or BenQ XL2411Z), but that is just a limitation of those particular products, and other monitors do accept 1080p 144 Hz signals over HDMI 1.4 without any modification or overclocking such as the ViewSonic XG2401. HDMI as a whole does not, and has never had, a 60 Hz limit.

    - A lot of confusing language is used when discussing connection interfaces (DVI, HDMI, etc.) which leads to these misconceptions. For example, maximum limits are often expressed as "HDMI 1.0 has a maximum limit of 1080p 60 Hz". But this does not mean HDMI 1.0 can't go higher than 60 Hz, and can't go higher than 1080p. It just can't go higher with both at the same time. Connection interfaces don't have maximum resolutions or maximum refresh frequencies. They have a maximum bandwidth, which is the combination of resolution and frequency (among other things). HDMI 1.3 increased the maximum bandwidth to just over double that of HDMI 1.0–1.2, allowing for up to 144 Hz at 1080p.

    + Some will argue "The extra bandwidth in HDMI 1.3 is only for 3D; it can't be used for 1080p 120+ Hz; Support for 120+ Hz at 1080p wasn't added until HDMI 1.4b/2.0". This is not really correct, and is based on a misunderstanding of what the word "support" means. HDMI does not need to have special "support" for any particular resolution or refresh frequency. Any resolution/frequency combination that falls within the bandwidth limit is allowed:

    @@ -1494,7 +1506,7 @@ Timing format (such as CVT, CVT-RB, or CVT-R2) slightly increases the data rate required for a video signal. Displays need small pauses in the data stream between frames (known as blanking intervals), so in order to keep the framerate the same, during the time the data stream is active, it needs to be sent at a slightly higher rate than if it were being sent continuously. As such, the cabling system needs to be able to handle this slightly higher data rate. CVT-R2 is currently the most efficient standardized timing format. The overhead introduced by blanking scales with framerate since more frames means more blanking intervals. If you include overhead for CVT-R2 timing, 8K 60 Hz with 24 bit/px color would require 49.7 Gbit/s, not 47.8.

    - So yes HDMI 2.1 does need to use compression to achieve 8K 60 Hz with 4:4:4 color, both in theory and in practice. According to the HDMI consortium, HDMI 2.1 implements VESA's DSC 1.2 compression algorithm for display modes beyond 8K with 4:2:0 color. DSC is claimed to be "visually lossless" (meaning yes it's lossy, but very unlikely to be noticeable), with near-zero latency and low cost/complexity, although no actual implementations of DSC have been seen in the market yet so no consumer testing has been done. + So yes HDMI 2.1 does need to use compression to achieve 8K 60 Hz with 4:4:4 color, both in theory and in practice. According to the HDMI consortium, HDMI 2.1 implements VESA's DSC 1.2 compression algorithm for display modes beyond 8K with 4:2:0 subsampling. DSC is claimed to be "visually lossless" (meaning yes it's lossy, but very unlikely to be noticeable), with near-zero latency and low cost/complexity, although no actual implementations of DSC have been seen in the market yet so no consumer testing has been done.
    @@ -1547,7 +1559,7 @@ Maximum Resolution / Frequency: - Equivalent to Single-Link DVI

    Show DVI Limits + Equivalent to Single-Link DVI

    Show DVI Limits @@ -1568,8 +1580,9 @@ An active adapter would be required to convert HDMI output to a full Dual-Link DVI signal, but at the time of writing I am not aware of any such adapters existing.

    -
    +
    Note 1: Any DVI-D device or cable will also work in a DVI-I port. If your display has a DVI-I port, you do not need to search specifically for an "HDMI to DVI-I" adapter. +
    @@ -1670,6 +1683,7 @@ Note 1: Resolution and refresh frequency limitations on active adapters are subject to each individual product's limitations. Read the product description.

    Note 2: Any DVI-D device or cable will also work in a DVI-I port. If your graphics card has a DVI-I port, you do not need to search specifically for a "DVI-I to DisplayPort" active adapter.

    Note 3: Mini DisplayPort is functionally identical to DisplayPort, the only difference is the physical shape. DisplayPort to Mini DisplayPort adapters can be used freely without affecting the operation or compatibility of other devices in any way. +
    @@ -1721,7 +1735,7 @@ Maximum Resolution / Frequency: - Equivalent to HDMI, version dependent on source HDMI version; see article below)

    Show HDMI Limits + Equivalent to HDMI, version dependent on source HDMI version; see article below)

    Show HDMI Limits @@ -1744,6 +1758,7 @@
    Note 1: Any DVI-D device or cable will also work in a DVI-I port. If your graphics card has a DVI-I port, you do not need to search specifically for a "DVI-I to HDMI" adapter. +
    @@ -1831,7 +1846,7 @@ Possible with a passive adapter? - Yes (DVI-I) / No (DVI-D) + No (DVI-D) / Yes (DVI-I) @@ -1998,7 +2013,7 @@ Possible with a passive adapter? - Yes (DVI-I) / No (DVI-D) + No (DVI-D) / Yes (DVI-I) @@ -2125,8 +2140,8 @@   - (Computer / Source) - + (Computer / Source) + - - + + - + - (Monitor / TV / Display) + (Monitor / TV / Display) @@ -2158,16 +2173,16 @@
    -
     
    +
     
    -
    +
    Click to Expand:

    - - + @@ -2191,14 +2206,14 @@ - +
    › + › Maximum Refresh Frequency and Resolution of Everything [Link]


    - - + @@ -2241,19 +2256,19 @@ It's pretty much the same as between DVI and HDMI / DP, just between the different versions of HDMI and DisplayPort instead. There is no difference in image quality between HDMI and DisplayPort. They both produce identical images when the same image settings are used. The choice between HDMI and DisplayPort only matters if one of them (usually HDMI) doesn't support the full specs of your monitor. For example, some 4K displays only have HDMI 1.4 and DisplayPort 1.2. Since HDMI 1.4 can't do 4K 60 Hz, but DisplayPort 1.2 can, you should use DisplayPort. However, if the monitor has an HDMI version which does support 4K 60 Hz (like HDMI 2.0), then it doesn't matter whether you use HDMI or DisplayPort.

    - You can check the maximum resolution and refresh frequency of each interface and version in the section above ("Maximum Refresh Frequency and Resolution of Everything"). + You can check the maximum resolution and refresh frequency of each interface and version here.

    - +
    › + › Which Cable Type Should I Use? (DisplayPort vs. HDMI vs. DVI vs. VGA) [Link]


    - - + @@ -2270,89 +2285,87 @@
    No. There are several different "levels" or "categories" of HDMI cables, rated by maximum bandwidth. This is not the same as an "HDMI version". HDMI version and feature support are not affected by cables. Even a Standard Speed HDMI cable can support an HDMI 2.0 or HDMI 2.1 connection between devices, and while the maximum bandwidth may be limited (the full 48.0 Gbit/s of HDMI 2.1 will not be available, for example), all other version-specific features such as HDR and VRR will still work. Using a so-called "HDMI 1.4 cable" (a High Speed HDMI cable) between two HDMI 2.0 devices will not "downgrade the connection to HDMI 1.4" and prevent all HDMI 2.0 features from working as some people believe; the only feature that is affected by the cable (besides inline Ethernet) is the maximum bandwidth, which is why cables are rated by bandwidth, and not by "HDMI version".

    -
    -
    -
    › + › Do HDMI Cables Have Versions? [Link]
    - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    - HDMI Cable Categories -
    - Certification Name - - Tested up to... - - Equivalent to (approx.)... -
    - Category 1 ("Standard Speed") - - 2.25 Gbit/s
    (75 MHz clock) -     		- 1280 × 720 at 60 Hz
    - 1920 × 1080 at 30 Hz -
    - Category 2 ("High Speed") - - 10.2 Gbit/s
    (340 MHz clock) -     		- 1920 × 1080 at 144 Hz
    - 2560 × 1440 at 75 Hz
    - 3840 × 2160 at 30 Hz
    -
    - "Premium High Speed" - - 18.0 Gbit/s
    (600 MHz clock) -     		- 1920 × 1080 at 240 Hz
    - 2560 × 1440 at 144 Hz
    - 3840 × 2160 at 60 Hz
    - 5120 × 2880 at 30 Hz
    -
    - 48G - - 48.0 Gbit/s
    (1.2 GHz clock) -     		- - 2560 × 1440 at 360 Hz
    - 3840 × 2160 at 180 Hz
    - 5120 × 2880 at 100 Hz
    - 7680 × 4320 at 50 Hz
    -     - (HDMI 2.1 uses compression to achieve higher modes like 8K 60 Hz) -
    -

    +
    + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
    + HDMI Cable Categories +
    + Certification Name + + Tested up to... + + Equivalent to (approx.)... +
    + Category 1 ("Standard Speed") + + 2.25 Gbit/s
    (75 MHz clock) +     		+ 1280 × 720 at 60 Hz
    + 1920 × 1080 at 30 Hz +
    + Category 2 ("High Speed") + + 10.2 Gbit/s
    (340 MHz clock) +     		+ 1920 × 1080 at 144 Hz
    + 2560 × 1440 at 75 Hz
    + 3840 × 2160 at 30 Hz
    +
    + "Premium High Speed" + + 18.0 Gbit/s
    (600 MHz clock) +     		+ 1920 × 1080 at 240 Hz
    + 2560 × 1440 at 144 Hz
    + 3840 × 2160 at 60 Hz
    + 5120 × 2880 at 30 Hz
    +
    + 48G + + 48.0 Gbit/s
    (1.2 GHz clock) +     		+ + 2560 × 1440 at 360 Hz
    + 3840 × 2160 at 180 Hz
    + 5120 × 2880 at 100 Hz
    + 7680 × 4320 at 50 Hz
    +     + (HDMI 2.1 uses compression to achieve higher modes like 8K 60 Hz) +
    +

    -
    While it is tempting to call High Speed HDMI cables "HDMI 1.4 cables", Premium High Speed cables "HDMI 2.0 cables", and 48G cables "HDMI 2.1 cables" because the ratings of those cables match the maximum bandwidth limits set by those HDMI versions, this should be avoided for the reasons explained above. HDMI versions define more than just bandwidth limits, and calling a High Speed HDMI cable an "HDMI 1.4 cable" implies that it is necessary in order to use HDMI 1.4 features, but this is not the case. You only need it to use the 10.2 Gbit/s bandwidth introduced by HDMI 1.3/1.4, not for the other features. For this reason HDMI cables are simply rated by bandwidth, not by "HDMI version".

    - Also note that the certifications do not actually tell you anything about the maximum bandwidth of the cable, except that it is at least the listed amount. A High Speed certification simply means the cable was tested at 10.2 Gbit/s and functioned properly at that speed. The maximum bandwidth that the cable can handle could actually be anything above that, be it 10.3 Gbit/s, 20 Gbit/s, or 100 Gbit/s. Of course, you might think "if it could handle all the way up to the next tier of certification, it would just be rated at that tier instead!"; well, yes you'd think so, but unfortunately that isn't always the case, as we'll see below.

    + Also note that the certifications do not actually tell you anything about the maximum bandwidth of the cable, except that it is at least the listed amount. A High Speed certification simply means the cable was tested at 10.2 Gbit/s and functioned properly at that speed. The maximum bandwidth that the cable can handle could actually be anything above that, be it 10.3 Gbit/s, 20 Gbit/s, or 100 Gbit/s. Of course, you might think "if it could handle all the way up to the next tier of certification, it would just be rated at that tier instead!"; well yes, you'd think so, but unfortunately that isn't always the case, as we'll see below.

    High Speed HDMI Cables and HDMI 2.0

    @@ -2366,19 +2379,23 @@
  • Category 2 ("High Speed") HDMI cables, which are tested to work at up to 10.2 Gbit/s
    • - The Premium High Speed HDMI certification did not exist at that time. Contrary to what some people believe, the HDMI 2.0 specification does not contain any kind of "HDMI 2.0 compliance test" for cables. No changes to the cable testing procedures or the requirements for passing the certification were made compared to HDMI 1.3/1.4.

    + The Premium High Speed HDMI certification did not exist at that time. Contrary to what some people believe, the HDMI 2.0 specification does not contain any kind of "HDMI 2.0 compliance test" for cables. No changes were made to the cable testing procedures or to the requirements for passing the certification compared to HDMI 1.3/1.4.

    - For the next two years following the release of HDMI 2.0, the HDMI Consortium insisted that cables which had passed the High Speed certification would be sufficient for the increased 18.0 Gbit/s bandwidth introduced in HDMI 2.0, and no higher levels of certification were introduced. During this time, a vast number of HDMI cables were manufactured which were capable of handling full HDMI 2.0 bandwidth (18.0 Gbit/s), but only received a High-Speed certification, the highest certification available at the time. Due to this, there are a large number of High Speed HDMI cables which do work at full 18.0 Gbit/s HDMI 2.0 bandwidth, despite not having the Premium High Speed certification. Most of these cables were never resubmitted for certification under the new certification tier once it was released, or if they were, they were sold again as a different product.

    + For the next two years following the release of HDMI 2.0, the HDMI Consortium insisted that cables which had passed the High Speed certification would be sufficient for the increased 18.0 Gbit/s bandwidth introduced in HDMI 2.0, and no higher levels of certification were introduced. For the most part, this turned out to be true, and many High-Speed HDMI cables (even ones that had been manufactured before HDMI 2.0 existed) did function with the increased bandwidth. Official statements from the HDMI Consortium together with many real-world examples combined to create a very solid belief that any certified High-Speed cable could handle HDMI 2.0 bandwidth, which is why many people still maintain that position to this day.

    - Many existing High Speed HDMI cables (manufactured long before HDMI 2.0) also worked fine with the increased data rates, but despite the HDMI Consortium's initial claims not all certified High Speed HDMI cables could handle it. Finally, after numerous complaints and reports during the two years following the release of HDMI 2.0, the HDMI Consortium revised their position on the matter and released a third cable certification tier, Premium High Speed HDMI, which actually tests cables for proper operation at 18.0 Gbit/s.

    + While it is true most of the time, it turns out not all High-Speed cables will work at the full 18.0 Gbit/s bandwidth, even if they have a valid High-Speed certification (not to mention the countless counterfeit non-certified cables on the market that are sold as "High-Speed"). This is particularly true with longer cables, in the 10–15 meter range (30–45 ft.). While they may be compliant with the High-Speed certification requirements, the majority of these cables will not work at full HDMI 2.0 bandwidth.

    + + Meanwhile during these two years, a vast number of HDMI cables were manufactured in the knowledge of HDMI 2.0, including longer cables which were capable of handling full HDMI 2.0 bandwidth (18.0 Gbit/s), but only received a High-Speed certification — the highest certification available at the time — despite being more capable than other longer cables already on the market. Due to this, there are many High Speed HDMI cables which do work at full 18.0 Gbit/s HDMI 2.0 bandwidth, despite not having the Premium High Speed certification. Most of these cables were never resubmitted for certification under the new tier once it was released, or were simply sold as a different product if they were.

    + + The failure of some High Speed cables at higher bandwidths was problematic for some though, and did not go unnoticed. Finally after numerous complaints and reports, the HDMI Consortium revised their position on the matter and released a third cable certification tier two years after the release of HDMI 2.0 called "Premium High Speed", which actually tests cables for proper operation at 18.0 Gbit/s.

    HDMI Licensing acknowledges the issue of some "high speed" cable not quite being up to the task of actually handling the full 2.0 bandwidth, saying:

    - "Although many current High Speed HDMI Cables in the market will perform as originally expected (and support 18Gbps), some unanticipated technical characteristics of some compliant High Speed HDMI Cables that affect performance at higher speeds have been found. These cables are compliant with the Category 2 HDMI Cable requirements and perform successfully at 10.2Gbps, but may fail at 18 Gbps."
    + "Although many current High Speed HDMI Cables in the market will perform as originally expected (and support 18Gbps), some unanticipated technical characteristics of some compliant High Speed HDMI Cables that affect performance at higher speeds have been found. These cables are compliant with the Category 2 HDMI Cable requirements and perform successfully at 10.2Gbps, but may fail at 18 Gbps."

    - So while many High Speed HDMI cables will handle the full 18.0 Gbit/s bandwidth of HDMI 2.0, it is not guaranteed, while a "Premium High Speed" HDMI cable has been tested to definitely work.

    + So while many High Speed HDMI cables will handle the full 18.0 Gbit/s bandwidth of HDMI 2.0, it is not guaranteed, while a Premium High Speed HDMI cable has been tested to definitely work. If you're buying a new HDMI 2.0 device like a 4K TV and you have some High Speed HDMI cables already, you may not need to replace them; you should check to see if they work before buying a new HDMI cable. If you are buying a new HDMI cable though, you should look for a Premium High Speed cable.

    For a more in-depth explanations, I recommend reading these articles:
    http://www.bluejeanscable.com/articles/note-about-hdmi-2.htm
    @@ -2386,14 +2403,14 @@
    - Close + Close

    - - + @@ -2458,7 +2475,7 @@ At 3840×2160 (4K):
    @@ -2487,7 +2504,7 @@ Notable examples of monitors which don't accept >60 Hz over HDMI are the BenQ XL2411(Z) and the ASUS VG248QE (which both use HDMI 1.4a). However, other monitors like the ViewSonic XG2401 do accept 1080p 144 Hz through HDMI 1.4a. - The refresh frequency limits of HDMI at some common resolutions are listed in the tables at the top of this guide under the heading "Maximum Refresh Frequency and Resolution of Everything". HDMI 1.3 and above are capable of 144 Hz at 1080p, and HDMI 2.0 is capable of 144 Hz at 1440p.

    + The refresh frequency limits of HDMI at some common resolutions are listed in the table here. HDMI 1.3 and above are capable of 144 Hz at 1080p, and HDMI 2.0 is capable of 144 Hz at 1440p.

    Can I use a DisplayPort to Dual-Link DVI passive adapter / cable?

    @@ -2537,14 +2554,14 @@ - +
    › + › Connecting to a 120+ Hz Display [Link]


    - - + @@ -2556,57 +2573,62 @@
    › + › Active vs. Passive Adapters [Link]
    - + - - - + - - + + + + - - - - - - -
    - Preface
    + What's the Difference? (Preface)
    + Passive Adapters
    - Doesn't passive adapter compatibility have something to do with analog and digital?
    + Passive adapter compatibility is completely arbitrary and has nothing to do with analog and digital
    - "But you can't convert between digital and analog passively!"
    + Passive adapter compatibility has nothing to do with bandwidth
    + Passive adapters are not necessarily limited to the lowest common denominator
    + Do passive adapters add any latency?
    + Do passive adapters reduce image quality?
    + Active Adapters
    + Do active adapters add any latency?
    + Do active adapters reduce image quality?
    + How can I tell if an adapter is passive or active?
    + Which type should I use?
    @@ -2615,20 +2637,39 @@ What's the difference between a passive adapter and an active adapter? (Preface)

    - The difference between an active adapter and a passive adapter is in the basic principle of operation. Telling the difference between a passive and active adapter isn't as simple as looking for external features like power cables or bulkiness. Some active adapters require power cables, but less complex ones can get enough power directly from the port. Some active adapters, like DisplayPort to VGA, can be very inexpensive, compact, reliable, and require no power cables, and for this reason they are often mistaken or mislabeled as "passive adapters". However, these external features are not the criteria which actually define whether an adapter is passive or active. + There are a lot of myths and confusion surrounding passive and active adapters, and there seems to be very little understanding of exactly what they are, how they both work, and how to identify them. Hopefully this article will help clear things up.

    + + First, to make some general points clear since there is a lot of misinformation spread around:

    + Passive Adapters: + + Active Adapters: +
    + + From a technical standpoint, the difference between an active adapter and a passive adapter is in the basic principle of operation. Being able to tell the difference between a passive and active adapter isn't as simple as looking for external features like power cables, bulkiness, or cost. Some active adapters require power cables, but less complex ones can get enough power directly from the port. Some active adapters, like DisplayPort to VGA, can be very inexpensive, compact, reliable, and require no power cables, and for this reason they are often mistaken or mislabeled as "passive adapters". However, these external features are not the criteria which actually define whether an adapter is passive or active.

    So what is the difference exactly? Well...

    - There are many different signalling formats, or methods of representing and transmitting the information that makes up a video signal. Each different interface (VGA, HDMI, DisplayPort, etc.) uses a different format; they represent the information in different ways. If you (as a system designer) want your device to be able to communicate information to another device which uses a different format, there are two ways for this to happen. You can design your device to be able to also recognize and communicate in the other device's format (make it "multi-lingual" in a sense), or you can insert a third-party device between them to convert the information from one format to the other. + There are many different signaling formats, or methods of representing and transmitting the information that makes up a video signal. Each different interface (VGA, HDMI, DisplayPort, etc.) uses a different format; they represent the information in different ways. If you (as a system designer) want your device to be able to communicate information to another device which uses a different format, there are two ways for this to happen. You can design your device to be able to communicate using the other device's format (make it "multi-lingual" in a sense), or you can insert a third-party device between them to convert the information from one format to the other en route (a "translator" if you will). A passive adapter works via the first approach, and an active adapters works via the second approach.

    +
    Passive Adapters

    - A passive adapter works via the first approach. As it turns out, the ports on your graphics card or laptop or other source device can output signals in multiple different formats. For example, DisplayPort ports are not just limited to sending DisplayPort signals; they can send signals in the HDMI or DVI formats if required. Of course, the only problem is that the DisplayPort port cannot physically morph itself into an HDMI port to allow you to plug in HDMI cables, so this is why the "passive adapter" is needed; the adapter does not do anything at all to the electrical signal, it is just there to change the shape of the port to allow you to plug the correct cable in. When you use a DisplayPort to HDMI passive adapter, the adapter is not "converting" DisplayPort signals into HDMI signals. The electrical signals coming from the DP port are already in the HDMI format, the adapter is just changing the physical shape of the port. + A passive adapter works via the first approach described in the preface. As it turns out, the ports on your graphics card or laptop or other source device can output signals in multiple different formats. For example, DisplayPort ports are not just limited to sending DisplayPort signals; they can send signals in the HDMI or DVI formats if required. Of course, the only problem is that the DisplayPort port cannot physically morph itself into an HDMI port to allow you to plug in HDMI cables, so this is why the "passive adapter" is needed; the adapter does not do anything at all to the electrical signal, it is just there to change the shape of the port to allow you to plug the correct cable in. When you use a DisplayPort to HDMI passive adapter, the adapter is not "converting" DisplayPort signals into HDMI signals. The electrical signals coming from the DP port are already in the HDMI format, the adapter is just changing the physical shape of the port.

    Since passive adapters don't actually do anything themselves, they will only work for some very specific combinations of ports which have been pre-designed with the ability to communicate in other formats. The table below shows which connections are possible using passive adapters: @@ -2706,11 +2747,53 @@
    This table is an exhaustive list of all possible connections that can be made using passive adapters between DP, HDMI, DVI, and VGA. If it is not listed above, it is not possible with a passive adapter. For specifics about which versions of DisplayPort and HDMI are supported by what, look up the specific adapter combination using the dropdowns at the top of this guide.

    - - Note that adapter compatibility is not symmetric. For example, even though a DisplayPort source supports passive adapters to HDMI displays, an HDMI source does not support adapters to a DisplayPort display. In fact nothing supports passive adapters to DisplayPort; the only way to connect to a DisplayPort input on a monitor is from a native DisplayPort connection or an active adapter. -

    + Passive adapter compatibility is completely arbitrary and has nothing to do with analog and digital

    + +
    + Looking at the table above, there are some interesting things to note.

    + + Although a DisplayPort output on your computer can support passive adapters to Single-Link DVI or HDMI inputs on your display, the reverse isn't true; DVI and HDMI outputs don't support passive adapters to DisplayPort input. This will come as a surprise to many people who assume that it does work because "they're both digital", and go around on forums advising people based on their assumption.

    + + In reality, being "both digital" means nothing in terms of adapter compatibility; DisplayPort supports adapters to DVI and HDMI because it is designed with that capability; meanwhile DVI and HDMI don't support passive adapters to DisplayPort, because they weren't designed with that capability. It's as simple as that, and it can apply to any interfaces, whether they are analog or digital. DVI-I supports passive adapters to analog VGA because it's designed with that capability. HDMI, DisplayPort, and DVI-D don't support passive adapters to VGA because they aren't designed with that capability. It isn't because "one is digital and the other is analog".

    + + There are no "rules of thumb" when it comes to adapter compatibility; it just depends on what capabilities each interface was designed with, which are arbitrary choices by the engineers that designed it. The only way to know whether passive adapters are compatible is to just know which interfaces support which adapters. Referring to the table above is a good place to start.

    +
    + + "But you can't convert between digital and analog passively!"

    + +
    + That's right, because you can't convert any signal to any other signal passively, whether it's digital to digital, digital to analog, or whatever. There is no such thing as "passively converting" signals at all; converting one signal into another is not how any passive adapter works. Instead, when a "passive adapter" is used, the source device outputs the original signal in whatever format is required, so no "conversion" is needed in the first place. This method of supporting adapters can be designed into any interface; there's no reason a port which normally sends digital signals can't be designed to send analog signals instead when an adapter is detected. +

    + + DVI-I is a perfect example of this; the port's main signal type (DVI) is digital, and it supports passive adapters to both HDMI (digital) and VGA (analog). When connected to an HDMI display via a passive adapter, the source device (graphics card) detects the HDMI display and starts using the DVI port to send HDMI signals instead of the normal DVI signals. DVI-I to VGA adapters work exactly the same way; when the graphics card detects a VGA display, it starts using the DVI port to send VGA signals instead of the normal DVI signals. Since passive adapters don't work by "converting" a DVI signal into an equivalent HDMI or VGA signal, the characteristics of DVI compared to the other signal are irrelevant. Passive adapters work because the DVI control chips are designed with the capability to output all these different types of signals. +

    + + So, just because "one's analog and the other is digital" doesn't mean passive adapters won't work; sometimes they do, sometimes they don't. Likewise, just because two signals are "both digital" doesn't mean passive adapters will work; sometimes they do, sometimes they don't.Whether signals are digital or analog actually has nothing to do with passive adapter compatibility. Passive adapters work if the port is designed to send the signal you want, and that's all there is to it. This is completely arbitrary and comes down to the design decisions of the engineers who drafted the standards and designed the chips. +

    +
    + + Passive adapter compatibility has nothing to do with bandwidth

    + +
    + Another surprise to most people is that DisplayPort 1.2 doesn't support passive adapters to HDMI 2.0, or that DisplayPort and HDMI don't support passive adapters to Dual-Link DVI, only to Single-Link DVI. Upon being informed of this, the response is usually something along the lines of "well that doesn't make any sense; they're both digital, and the bandwidth of DisplayPort is greater than Dual-Link DVI / HDMI 2.0, etc. so a passive adapter should work!" But again, this is based on a misunderstanding of how passive adapters work.

    + + People imagine that a passive DP to DVI adapter is "converting" DisplayPort signals into DVI signals, as if the image is originally sent as a DisplayPort signal and an adapter transforms it into an equivalent Dual-Link DVI signal, which should work because any Dual-Link DVI data stream will "fit" inside a DisplayPort signal since the bandwidth of DisplayPort is greater than that of DL-DVI. This is all very sensible sounding, and is a wonderful description of how an active adapter works, not a passive adapter.

    + + A passive adapter does not "convert" a signal from format to another. The original signal is sent in the desired format to begin with, and the adapter is just changing the physical shape of the port so that the correct cables can be plugged in. In a DisplayPort to DVI (or HDMI to DVI) passive adapter, the DisplayPort output port is essentially used as a DVI port; all of the pins are used to send the same electrical signals that a DVI port's pins would. Of course, the DisplayPort port is still shaped like a DisplayPort port and so DVI cables will not fit — that's what the passive adapter is needed for — but electrically it is acting as a DVI port. But a DisplayPort port also only has 20 pins (compared to 19 pins on SL-DVI-D and 25 pins on DL-DVI-D), so it can only send signals that a Single-Link DVI port would send; it is physically impossible for it to send Dual-Link DVI signals in this manner, because it simply doesn't have enough pins to send the same signals that a DL-DVI port would. HDMI ports (which have 19 pins) are also subject to the same restriction; they can only send Single-Link DVI signals, not Dual-Link.

    + + And again a similar concept applies to DisplayPort to HDMI adapters; many people are perplexed when they discover that DisplayPort 1.2 only supports adapters up to HDMI 1.4. "But DP 1.2 has more bandwidth than HDMI 2.0!" Yes it does — but since adapters don't work by "converting" DisplayPort signals into equivalent HDMI signals, it doesn't matter if HDMI 2.0 signals "fit" inside a DisplayPort 1.2 signal. The bandwidth of DisplayPort is irrelevant, because there are no DisplayPort signal involved at all. DisplayPort 1.2 only supports adapters to HDMI 1.4 because the DisplayPort control chips are not designed to send HDMI signals greater than that (mostly because DisplayPort 1.2 was published in 2009 and HDMI 2.0 didn't exist until around 2013 or so). DisplayPort 1.3 (2014) does support passive adapters to HDMI 2.0.

    +
    + + Passive adapters are not necessarily limited to the lowest common denominator

    + +
    + Another bit of seemingly sensible wisdom which turns out to be not always true is that when using a passive adapter, you'll be limited to lowest capabilities of the two interfaces involved. For example, if using a DVI to HDMI adapter, many people will tell you that audio won't work. After all, DVI signals contain no audio, and converting an audio-free signal to the HDMI format won't make audio magically appear. But again, this is based on the idea that an adapter "converts" DVI signals into HDMI signals, so this is information that applies to active adapters, not passive adapters. When using a passive adapter from a DVI source to an HDMI display, the output device detects an HDMI display and sends HDMI signals to it, including audio. Whether DVI signals contain audio or not is irrelevant, because there are no DVI signals involved. The adapter isn't "converting" DVI signals into HDMI signals, the signals are sent in the HDMI format to begin with.

    + + While it is sometimes true that you'll be limited to the lowest capabilities between the two interfaces, it isn't always true. Check the specific adapter combination you are wondering about using the dropdown interface at the top of this guide.

    +
    + Do passive adapters add any latency?

    @@ -2802,14 +2886,14 @@
    - Close + Close

    - - + @@ -2847,19 +2931,19 @@
    - +
    › + › Active Adapter Requirements for Multi-Monitor Configurations [Link]



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    › Bandwidth / Maximum Refresh Frequency Calculator [Link][Link]
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