Does a HDMI-to-DVI (dual link) adapter exist? I don't care about the price

Solution 1:

I'm writing this on a 2560x1600 Dual Link DVI monitor connected to a computer using HDMI 1.4.

Stop searching for HDMI to DVI-DL adapters. All adapters that you'll find are passive single-link adapters, even though they may be advertised as dual-link.

Although a HDMI 1.4 to Dual Link DVI adapter is possible to implement using an Analog Devices ADV7619 297 MHz HDMI 1.4 receiver that does automatically split high pixel clock links into odd and even pixels and two ADV7513 165 MHz HDMI 1.4 transmitters to transmit the pixels over two separate links, no manufacturer is making such a device.

You need a device that generates Dual Link DVI output from a single link input. And the only one that's widely available is a DisplayPort to Dual Link DVI adapter, sold under several different brands.

With that, we've reduced the problem to converting HDMI 1.4 to DisplayPort 1.1. There were no solutions for this until recently, when the STMicroelectronics chip STDP2600 became available. Several brands sell adapters based on this chip. In case your monitor takes a DP input at full resolution, using only this adapter is enough - no need to convert to DVI-DL.

Connecting those two together should provide a HDMI 1.4 to Dual-Link-DVI solution. However, the Linux Radeon driver (xf86-video-ati) was still not happy with it, and ignored the 2560x1600 videomode in the list of valid modes in EDID. The reason was that the Linux Radeon driver would enable pixel clocks above 165 MHz only in case a monitor has a HDMI Vendor Specific Data Block in the Consumer Electronic Association extended block of EDID.

Obviously, a pure DVI monitor will not have a HDMI VSDB in CEA EB of EDID. I solved that by adding a S/PDIF audio de-embbedder for HDMI that I got off eBay into the chain that adds the CEA EB to add audio descriptors to EDID. A proper solution would be to provide a modified EDID file directly to the driver.

This works for Linux, on Windows you may not need the EDID change, or you may need a more extensive one. I don't have a Windows machine to test.

String all three together, make sure all are powered up via their USB connectors and voilà, beautiful full resolution 2560x1600 picture at 60 Hz refresh rate on my Dual Link DVI monitor.

Solution 2:

I normally shy away from shopping recommendations, but this is not your run of the mill requirement and requires a bit of specialist insight. These are the guys to talk to about standards conversion:

Kramer Electronics

They have a distribution amp that takes HDMI and sends it out on HDMI + displayport at resolutions up to 2560x1600 but it states hdmi 1.4: http://www.kramerus.com/products/model.asp?pid=1213

As I understand it, there are technical issues converting hdmi to true DVD-D, but these are the guys to advise you.

Solution 3:

For 2560x1440 you need an active adapter but it also have to explicitly support the resolution and dual links. This requires an additional power source.

This is the only adapter i found that really supports this resolution and even a bit higher (2560x1600).

http://eu.startech.com/AV/Displayport-Converters/Mini-DisplayPort-to-DVI-Dual-Link-Active-Adapter%E2%80%93USB-Powered~MDP2DVID

Solution 4:

http://www.ldlc-pro.com/fiche/PB00034665.html or similar; price < $10. It's usually provided with new laptops anyway, I didn't even have to buy one. Such adapters really work (tested yesterday), but of course you need a dual-DVI-D cable. And a female HDMI to female HDMI adapter.

If like me you can't get a higher res that 1080p, this is most likely due to the HDMI component of the motherboard; but there is a neat workaround for this : simply go in the drivers settings, and create a new custom resolution.

At least NVIDIA has such an option; I don't know about AMD. It will display a "we take no responsability for this !" warning, btw. Some users report that using 60Hz work fine at first, but crashes at restart. Use 35Hz instead.

For information, I have a Dell laptop with NVIDIA Optimus ( GTX 525M and Intel GMA 3000 at the same time ) and a Dell U3011 monitor. This solution works at 2560x1600 @ 35Hz

The follwing is an edit by user joevt. I'm not sure I agree with it.
Note that the adapters listed are single link only even though they may say dual link DVI. 2560x1600 @ 35Hz works because it's slow enough for single link DVI (pixel clock is less than 165 MHz). Anything faster for DVI such as 2560x1600 @ 60Hz requires dual link DVI which these HDMI adapters do not support. HDMI is single link but allows for pixel clocks up to 340 MHz (HDMI 1.3 or greater). To convert dual link (e.g. 2 pixels @ 134 MHz) to single link (e.g. 1 pixel @ 268 MHz) requires additional circuitry in the adapter.