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- #21
Jeff Kilgroe
Well-known member
As for interfaces - 1920x1200 is max res for single link DVI AFAIK.
It can do a bit higher than that, but I think that's pretty much the highest any of the vid card makers allow in their drivers. I know that to get anything I've seen with 2048 pixels wide or more, it has been on a dual-link interface.
Dual link DVI can do 2560x1600. Twin dual link can drive 3840x2400 that I've seen. But 4096x2304 may well require another bus - anybody know for sure? Oh, and that 3840x2400 was at some woefully, horrifically slow refresh rate - like 16Hz or something on a Mac Pro at IBC last year.
I'm driving dual 30" here on an FX4500 card. That's 5120x1600 @ 60Hz, and that's 1.1MP short of 3840x2400, which still isn't a problem. At least not at 8bits/channel. The older IBM/ViewSonic 22" 3840x2400 displays could handle this resolution via quad DVI (2 x dual-link w/splitters). But they unfortunately have terribly slow refresh at full resolution. Those displays essentailly use the same 1920x1200 DSP system to process each input in series, so you're getting a refresh of about 15Hz for the entire display. I recall someone mentioning that these 22" displays are what was being used at IBC, so there's a good bet that's the problem.
From what I can make of the DVI specs, 2x dual-link DVI interfaces should drive the 4096x2304 from RED just fine at 8bits/channel RGB up to 60Hz. For 10bit or greater, lower refresh rates will be fine, but for 60Hz, it looks like something more will be required.
The upcoming display interface offerings like DisplayPort may help in this regard. Although, DisplayPort seems more consumer oriented... I can't recall the name of the other one that is being supported by Apple and a few others, but it should provide the equivalent bandwidth of at least two dual-link DVI interfaces on a single cable. Actually 4 on a single cable as I think it has a "dual-link" capability of its own. So this may be the answer. But I don't know the specs, just what I've heard.