Dual-DVI Radeons!!!

[Ribbit]

I was just over at Rage3D, and noticed on their front page (scroll down a little) that Sapphire are planning dual-DVI versions of the 9800Pro/XT. Just thought I'd post it here, since I know a lot of people here would be interested.

Now if ATi would just let the Linux DRI guys have R300 specs....

[rylan]

Nice That would basically kill any reason to stick with Matrox cards.

[UtwigMU]

There are already nVidia dual DVI cards from Asus and Gainward and people still buy Matrox and Ati cardds.

[rylan]

Well it'll depend on the price, but to be honest I don't understand why people will continue to buy Matrox cards such as the P750 when you can get a radeon 9800 with dualdvi that actually has some performance for a lot less.

[bsdgeek]

And the details of the card. Can the Radeon do independent dual DVI with a max resolution of 1600x1200? Overlay on both outputs?

And there's always triplehead to get people to buy Matrox.

[Wombat]

Originally posted by bsdgeek
And there's always triplehead to get people to buy Matrox.

That depends on how well SurroundView works.

[Ribbit]

I'm pretty sure that all Radeons, and certainly the R300s, can do at least 1600x1200 on both outputs. As for overlay, there's only one, but it can be put on either output. That might be a must-reboot setting though, I know it can't be set dynamically on XFree86.

The Radeons can do independent dual display, but I'm not certain that both heads are accelerated. Obviously they'll both be accelerated in merged display mode.

What else? Matrox still have the edge in signal quality, but ATi aren't far behind, and if you've specifically bought a dual-DVI card then it's probably not an issue anyway.

Triplehead may or may not be matched by SurroundView, as Wombat said. But that needs an IGP motherboard, so I guess Matrox still have the advantage there.

Matrox still have the reputation for stable drivers, which are important to the music/video studio guys, and the financial sector probably still see them as the multi-display guys. But ATi, and to a lesser extent nVidia, are working hard on both those fronts, and Matrox' advantage there is shrinking all the time.

[bsdgeek]

Originally posted by Ribbit
I'm pretty sure that all Radeons, and certainly the R300s, can do at least 1600x1200 on both outputs. As for overlay, there's only one, but it can be put on either output. That might be a must-reboot setting though, I know it can't be set dynamically on XFree86.

The Radeons can do independent dual display, but I'm not certain that both heads are accelerated. Obviously they'll both be accelerated in merged display mode.

Things are different with DVI, many cards do not support 1600x1200 at all, much less on both heads if they are dual DVI. I'm not sure if it's a limitation on other dualDVI cards but even Parhelia can't do dual independent mode on DVI (The PSeries apparently can).

[Ribbit]

OK, can someone explain to me why this should be the case? After all, as far as I can see, a DVI output isn't really any different to an analogue output, as far as the rest of the hardware is concerned. In fact, it should be less restricting, since it's "pixel clock" is only up to 165MHz, compared to potentially 400MHz with an analogue output.

[XHotKolaX]

Originally posted by bsdgeek
I'm not sure if it's a limitation on other dualDVI cards but even Parhelia can't do dual independent mode on DVI (The PSeries apparently can).

Apparently it can, mate, as I'm using it.

[bsdgeek]

http://matrox.com/mga/products/parhelia/home.cfm

** Please note that resolutions, color depths and refresh rates must be the same on each display when using Dual-DVI; however, Windows recognizes the two displays as independent devices and will therefore treat the desktops on each display as independent as opposed to one extended desktop (Win NT style)

Maybe it's wrong, I don't know. I don't have 2 DVI monitors (or one for that matter ) to see for myself.

[rylan]

Remember that DVI uses TMDS, which is encoded serialized data. Single-link DVI is 3 channels of data up to 165MHz, with each channel handing an 8bits of color data plus syncs and encoding information. So your asic needs bandwidth of 1320Mbps per channel, not including the other sync/encoding data. Thats some screaming serializers to deal with when you have the tmds driers integrated in your asic.

[DGhost]

I have one of the XFX GeForceFX 5700 Ultra Dual-DVI's. Only thing i could get my hands on in America that was dual DVI and not more expensive than I paid for my Parhelia (or would fit in my shuttle SFF box). It is really, really nice.

DVI really removed the major benefits that the Parhelia had. Picture quality is great, software support is great, and i have had zero problems with it. it supports native dual-display support, 3d acceleration on both (although the second head is not quite as good as the first), etc etc. All the fun stuff that you have come to love and expect. And it can still play new high end games nicely.

The only major thing that the Parhelia has that it does not (especially when running 2x DVI) is the second hardware overlay. that being said, i don't really use overlays all that much anyways so its not a big deal. FSAA is nice, but i get the feeling it won't be enabled too much anyways. native resolution looks better than streched + FSAA.

[XHotKolaX]

Originally posted by bsdgeek
http://matrox.com/mga/products/parhelia/home.cfm


Maybe it's wrong, I don't know. I don't have 2 DVI monitors (or one for that matter ) to see for myself.

Perhaps we're misunderstanding each other?

Dual independant is when you can have two desktops and either of them can be an independant resolution.

Dual extended is when both monitors have to be the same resolution. Windows treats it as one big display rather than 2 seperate.

I can switch between either one without a problem. Extended allows gaming on both heads, independant doesn't.

Independant doesn't blank your secondary monitor so you can keep track of your other programs while playing a single head game.

[bsdgeek]

Can you use different resolutions and/or refresh rates?