Re: [Dri-devel] High-resolution monitors (T221)

[Roland S. <rsc...@hi...>]

Linus Torvalds wrote:
> The thing is a 3840x2400 pixel monster, and to drive it at reasonable
>  frequencies you actually need to support a quad DVI setup where it 
> looks basically like four monitors running at 1920x1200. And from 
> what I can gather by googling, the outputs need to be synchronized, 
> so you really need to have a card like the NVidia Quadro4 XGL or 
> similar (ie you can apparetly _not_ drive it with multiple separate 
> video cards).
> 
> Apparently it also does work with just a single DVI thing (ie reports
>  of it working with the Radeon 8500 at least on macs), probably at a 
> much reduced frequency (ie a single DVI link should be able to drive 
> the thing at something like 10Hz refresh rate - I think the Radeon 
> 8500 supports two links on its single DVI-I interface, so should get 
> up to 20Hz?).
I don't know of much cards which have dual-link tmds. Even all the
Quadro4 XGL cards only have 2 single tmds links. The Quadro NVS 400
(PCI) supports 4 single links, but I have no idea if there is linux/3d
support in the driver (basically I believe this is just 2 GeForce4MX 420
chips on one board). If you get the Quadro FX 2000 or 3000 (but not
1000), it has one dual-link and one single-link DVI connectors. All ATI
consumer cards have only 1 single tmds link (there were announcements
from tyan about dual-dvi cards, but the cards were apparently
cancelled). The firegl cards (at least the newer ones based on the
"gaming chips") have two single tmds links.

> The binary-only NVidia driver supports it at the full 40Hz frequency,
>  so I know I can get the thing to work under Linux in case I decide
> to waste the money on it (or, preferably, convince my employer to do
> so ;)
I assume you can get the 40Hz only with the FX2000/3000?
The reviews I read stated something like 12Hz if they only used 1 dvi
output of a Quadro4 XGL, and double of that (but with tearing due to
sync issues in 3d - not sure if this is driver fixable) if they used
both dvi connectors.

> However, I was wondering if anybody knows of somebody using it with 
> proper opensource drivers.. Or is just otherwise confident for some 
> technical reason that it should work..
> 
> I'd want 3D acceleration to work, but I don't care if it ends up 
> being limited to smaller areas (ie if the canvas size has to be 
> limited to 2048x1536 or something, who cares?).
If I'm not mistaken it doesn't work currently, however ATI's windows 
drivers support larger resolutions (with 3d), so it looks like it's 
possible to work around the chip limits (which is 2560x2560 for the r300 
(and derivatives) and 2048x2048 for the r200). Last time I checked ATI's 
linux driver didn't support those larger resolutions (if 3d is enabled) 
however.

> Damn, but it's a drool-inducing piece of hardware.
Unfortunately still out of my price range by quite a bit...

Roland