Topic on Glossary talk:Graphics card

This page shows the changes between two versions of a post by Mirh in the topic "Cables, interfaces, and you" on Glossary talk:Graphics card. You can see other versions of this post at its history page.

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 We don't have an article about display interfaces, so here's a roundup of problems:
 * Despite [[Wikipedia:VGA connector|DE-15]] being technically compatible with SCART, component, composite and whatnot, passive adapters (but even a lot of "normal" active ones, which are just meant to go from a modern digital connection to PC VGA) won't work with most older TVs due to just-too-different [[Wikipedia:Component video sync|video sync signals]], [https://old.reddit.com/r/crtgaming/wiki/connectors-and-interfaces#wiki_interfaces scan rate] or color space.
-:* RGB-to-CRT hacks, [https://emulation.gametechwiki.com/index.php/Display_FAQ custom cabling], having a [[Wikipedia:Multisync monitor|multisync magic box]] or an old [[Wikipedia:Video-in video-out|VIVO]] card are all possible solutions. Or you could just buy a direct converter between the two desired standards.
+:* RGB-to-CRT hacks, [https://emulation.gametechwiki.com/index.php/Display_FAQ custom cabling], having a [[Wikipedia:Multisync monitor|multisync magic box]] or an old [[Wikipedia:Video-in video-out|VIVO]] card are all possible alternatives (if not the ''only'' ones [https://www.youtube.com/watch?v=puu-iyTsZtg&t=69s available], for the highest end use cases)
-* Not only monitors may support different "overt features" depending on the protocol ''and'' port they are hooked with, this can even affect [https://www.prad.de/testberichte/test-monitor-samsung-2494hm/7/ input lag]
+* Not only may monitors support different "overt features" depending on the protocol and version of the port they are currently hooked with, this factor can even [https://www.prad.de/testberichte/test-monitor-samsung-2494hm/7/ affect] [https://www.avsforum.com/threads/input-lag-wars-post-your-input-lag-results-of-your-lcd-display-here-for-reference.1131464/page-168#post-21438238 input lag] <small><small>(let alone the [https://www.rtings.com/tv/reviews/samsung/ks8000#test_14 absolute] [https://youtu.be/F9OvPfPd8s0?t=646 madness] that the TV world is)</small></small>
-* The final capabilities and bandwidth of a video connection is determined by the greatest common divisor between the GPU-transmitter, cables (and/or possible adapters), and display-receiver:
+* The final capabilities and bandwidth of a video connection is determined by the greatest common divisor between the GPU display engine block, the physical link encoder, cables (and/or possible adapters), and display-receiver:
-:*VGA has the RAMDAC frequency to set bounds, while DVI and HDMI terms are set by the TMDS clock. These can often lead to lower supported resolutions than the official maximum of the protocols, especially on laptops (I have yet to hear about similar unexpected shortcomings in DP though)
+:*Data rate bounds are set by the RAMDAC frequency for VGA, while DVI and HDMI terms are set by the TMDS clock. These can often lead to lower supported resolutions than the official maximum of the protocols, especially on laptops (I have yet to hear about similar unexpected shortcomings in DP though)
-::* these [https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU limitations], which can be even more paradoxical with adapters in-between, can be sometimes worked around (even with respect to the official specification), particularly on linux.
+::* these [https://www.monitortests.com/blog/common-pixel-clock-limits/ limitations], which can be even more paradoxical with adapters in-between, can be sometimes worked around (even with respect to the official specification), particularly on linux.
-::* display controllers are also programmable ([https://www.guru3d.com/news-story/nvidia-releases-firmware-update-tool-to-support-displayport-1-3-and-1-4-displays.html as] [https://www.intel.com/content/dam/support/us/en/documents/graphics/HDR_Intel_Graphics_TechWhitePaper.pdf seen] [https://www.thesixthaxis.com/2010/06/17/how-ps3-outputs-3d-video/ many] [https://arstechnica.com/gaming/2016/09/whats-up-with-ps4s-surprise-firmware-update-is-4k-around-the-corner/ times]) and features are [http://www.edepot.com/playstation3.html#PS3_HDMI almost] never theoretically unachievable. Still, OEMs on the cheap might even end up [https://linustechtips.com/topic/1306077-hdmi-21-on-3000-series-laptops/?do=findComment&comment=14485966 downgrading] what you'd expect from a product.
+:* As far as "features themselves" are concerned instead, display controllers are relatively programmable ([https://www.guru3d.com/news-story/nvidia-releases-firmware-update-tool-to-support-displayport-1-3-and-1-4-displays.html as] [https://www.intel.com/content/dam/support/us/en/documents/graphics/HDR_Intel_Graphics_TechWhitePaper.pdf seen] [https://www.thesixthaxis.com/2010/06/17/how-ps3-outputs-3d-video/ many] [https://arstechnica.com/gaming/2016/09/whats-up-with-ps4s-surprise-firmware-update-is-4k-around-the-corner/ times]), and these are [http://www.edepot.com/playstation3.html#PS3_HDMI almost] never ''theoretically'' unachievable.
-:* Cables [[Wikipedia:DisplayPort#Cables|don't]] [[Wikipedia:HDMI#Cables|have]] "versions" (well, except HDMI w/ ethernet which is separate by design I guess). You only have a minimum guaranteed bandwidth certification, which the actual cord could also easily exceed in practice.
+::* it goes without saying though, the GPU drivers are paramount in doing anything. And when it's not for the flip-flopping bugs <small><small>(best to draw a veil over this)</small></small> they still have arbitrary blocks, from [[Glossary:Variable refresh rate (VRR)|VRR]] to [https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU?page=550#pid11511 chroma subsampling]. Sometimes even the specification itself can be [https://www.monitortests.com/forum/Thread-custom-resolution-4k-2160p60hz-4-2-0#pid6580 too stupid] for its own sake.
+:* "Embedded" applications (i.e. about anywhere that isn't a desktop PC) have [https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1922754 less] stricter (and uniform) [https://linustechtips.com/topic/1306077-hdmi-21-on-3000-series-laptops/?do=findComment&comment=14485966 requirements] on the transmitter chip bridges <small>(this is most notable in the TV world with the most disparate subsets of HDMI 2.1 limitations)</small>
+:* Seriously, adapters are a [https://github.com/torvalds/linux/commit/6bffebc90c23e2341a1f8371e7b496ec94136e47 can] [https://www.phoronix.com/scan.php?page=news_item&px=mtq4mde of] [https://github.com/torvalds/linux/commit/fd952d436446cffdf97a61bf456a0987011e42e0 worms].
+:* Strictly speaking, cables [[Wikipedia:DisplayPort#Cables|don't]] [[Wikipedia:HDMI#Cables|have]] "versions" (well, except HDMI w/ ethernet which is separate by design I guess). You only have a minimum guaranteed bandwidth certification, which the actual cord [https://youtu.be/XFbJD6RE4EY?t=231 could] [https://www.youtube.com/watch?v=Vn2vdQZhs0w also] easily exceed in practice.
 :* Of course there are [https://www.hdblog.it/2015/01/24/HDMI-20-differenze-tra-full-e-draft/ all] [https://www.dell.com/support/kbdoc/en-is/000126493/setting-up-the-p2415q-p2715q-monitors-with-hdmi-2-0-that-support-4k-x-2k-60hz similar] [https://old.reddit.com/r/bravia/comments/jdejop/why_the_xh90_x900h_cant_do_4k120hz_in_dolby/ kinds] of problems on the screen's end too.
-::* not last, since HDMI for some whimsical reason [https://www.avsforum.com/threads/2019-c9%E2%80%93e9-owners-thread-no-price-talk.3057634/page-432#post-58759564 cannot have] the YCbCr 4:2:2 bit depth measured (the thing actually always being [https://forum.kodi.tv/showthread.php?tid=332180&page=8#pid2760493 carried] on a 12-bit signal), some displays will report "8 bit" as a placeholder value
+::* not last, since HDMI for some whimsical reason [https://www.avsforum.com/threads/2019-c9%E2%80%93e9-owners-thread-no-price-talk.3057634/page-432#post-58759564 cannot have] the YCbCr 4:2:2 bit depth measured (the thing actually always being [https://forum.kodi.tv/showthread.php?tid=332180&page=8#pid2760493 carried] on a fixed 12-bit signal<small>?</small>), some displays diagnostics menus can report "8 bit" as a placeholder value
-::* tinkering around bandwidth limitation of the interface is even more of a [https://old.reddit.com/r/OLED_Gaming/comments/k40p42/oled_as_an_ultrawide_display_for_nvidia_users/ nightmare] when the usual [[Glossary:Scaling#GPU/Display scaling|caveats]] meet [[Glossary:High dynamic range (HDR)|HDR]]
+::* tinkering around bandwidth limitation of the interface with [[Glossary:Custom resolution|custom resolutions]] is even more of a [https://old.reddit.com/r/OLED_Gaming/comments/k40p42/oled_as_an_ultrawide_display_for_nvidia_users/ nightmare] when the usual [[Glossary:Scaling#GPU/Display scaling|troubles]] meet [[Glossary talk:High dynamic range (HDR)|HDR]]
-::* many TVs may outright refuse even when [https://www.rtings.com/tv/tests/inputs/supported-resolutions forced] any non-standard (as in, anything that isn't commonly found in "home theatre" settings) resolution
+::* many TVs may outright refuse any non-standard (as in: anything that isn't commonly found in a "home theatre" setting) resolution, even when [https://www.rtings.com/tv/tests/inputs/supported-resolutions forced]
+::* this is at least still better than [[PC gaming on a TV and couch#Chroma Subsampling over HDMI and HDTVs|the past]], when they may have set the color space [https://forum.kodi.tv/showthread.php?tid=323825&page=2#pid2667303 based] on the resolution, or they didn't support non-subsampled 4:4:4 colours either (HDMI technically requires accepting a RGB color format, but that says nothing about processing and final presentation)
+::* "Just Scan" has always been important to avoid overscan at least on certain trashy displays ([https://forum.kodi.tv/showthread.php?tid=58604 caveats]), but despite being found under the aspect ratio settings it technically entails much more than just that. Some newer features may [https://old.reddit.com/r/OLED_Gaming/comments/mm4cl9/is_prevent_input_delay_input_lag_option_on_c1g1/ require] or [https://forums.blurbusters.com/viewtopic.php?f=2&t=3823&start=320#p34586 disavow] it
+::*all your base are belong to [[Wikipedia:Extended Display Identification Data|EDID]] (which can always be fixed with CRU, but a slightly [https://old.reddit.com/r/Monitors/comments/lfqjvz/open_letter_to_lg_regarding_27gl850_and_its_issues/ different] one could even prevent the GPU from ever going idle)