Bonjour, merci pour votre réponse :)
Le problème ne vient pas de la CG: je tourne avec une 670 en attendant, qui possède elle aussi des ports DP et HDMI et rien ne fonctionne avec celle-ci non plus alors que je n'ai aucun souci avec mon câble DVI/DVI. J'ai trouvé une réponse au pourquoi du comment sur un forum américain:
When using passive adapters, you are not "converting" DVI signals into HDMI signals. Passive adapters work because the video ports on graphics cards have the ability to output multiple types of signals. For example a DisplayPort port doesn't have to send DisplayPort signals. It can also send HDMI signals or DVI signals instead of DisplayPort signals (not "converting" DisplayPort signals into DVI/HDMI signals). The only problem of course is that the DisplayPort port can't physically morph itself into an HDMI port to allow you plug in HDMI cables, so this is why the adapter is needed, it is merely changing the shape of the port to allow you to plug things in, it doesn't do any kind of conversion.
Likewise, DVI ports on graphics cards will send HDMI signals instead of DVI signals if it detects being plugged into an HDMI display. The DVI to HDMI adapter simply changes the shape of the port, it does not "convert" DVI signals into HDMI signals. So the question of what DVI supports is actually irrelevant, since there are no DVI signals involved here. The port is sending HDMI signals out to an HDMI display, so the question is really whether HDMI supports 1440p 60 Hz, and the answer is... yes, but it's finicky and may require a custom resolution.
On the topic of adapting Dual-Link DVI to HDMI, you are correct this is physically impossible. Even though you will find plenty of "Dual-Link DVI to HDMI" adapters for sale, all of them are fake, they are just Single-Link DVI to HDMI adapters in disguise. The extra Dual-Link pins are simply dummies and are not connected to anything. HDMI only has 19 pins, the same as Single-Link DVI, there are no more spots for those extra DL-DVI pins to connect to on the HDMI side of the adapter.
So how can we get 1440p 60 Hz over these adapters if DVI requires a Dual-Link connection to support that, and these adapters are only Single-Link? Well again, what DVI does or doesn't support is irrelevant, because we are not using DVI. We are using HDMI, it's just that the HDMI signal is being routed through the DVI port, we are not "converting" a DVI signal into an HDMI signal, and so the limits of a Single-Link DVI connection don't come in to play. HDMI does support 1440p 60 Hz with only 19 pins, so everything is good here. Using a DVI to HDMI adapter is exactly the same as using a native HDMI port, including support for inline audio, 4K 60 Hz (if the card supports HDMI 2.0), etc.
Just remember this doesn't apply in reverse. If you flip that adapter around (plug in a graphics card's HDMI port to a DVI display), the graphics card will detect that and start sending Single-Link DVI-D signals instead of HDMI signals (HDMI ports don't have enough pins to be used Dual-Link DVI ports, like I said), and so you'll be limited to 1920—1200 at 60 Hz with no audio and no VGA adapter compatibility, just like any other Single-Link DVI-D port. |
