Windows 7 3D Application Performance with Multiple Graphics Cards

[Sajuuk]

Hey guys. I remember reading about people who have had performance issues running wow over multiple graphics cards and monitors. So after having installed Windows 7 on my computer, I decided to see the difference in performance if I tried playing a Windowed Game (In this case, Crysis Warhead) over multiple monitors, spanning multiple graphics cards.

Previously as I understand it if you had multiple graphics cards and tried switching a 3D applications from one monitor to another where the monitors were hooked up to different graphics cards you got a significant drop in performance. So, out of curiousity I decided to fire up a more graphically intensive program at my disposal...in this case - Crysis Warhead, and see if I got any difference in performance across multiple monitors/graphics cards in windowed mode.

Why not World of Warcraft? I've let all of my accounts go inactive from lack of interest in the game, and while it would be a good way to test picture in picture swapping from within Keyclone/Innerspace, I don't feel like reactivating my accounts. So for this test I'm just going to put Crysis Warhead into windowed mode and drag it between screens.

My Testing Rig, aka the Furnace:
i7 920 at 3.5Ghz cooled on Air, 12Gb DDR3 1333, Dual 9800GX2s. 32GB SSD, 250GB/1TB drives, four monitors - 22", 20", 19", 19", resolutions at 1680x1050, 1680x1050, 1280x1024, 1440x900.

For testing and easy dragging in between monitors, I ran Crysis Warhead at 1280x1024, 0xAA, all settings on Enthusiast.
Pictures and explanation. - Only editing was converting to JPEG, and labeling the monitor/gpu association in the layout picture.

Here is the way my monitors are arranged. You can see the borders of where the monitors start/stop by looking at the wallpaper, I've labeled the top/bottom monitors as GPU1/GPU2.

As these are extremely large (dimension wise, none of them are over 1.5MB in actual size) I'm giving you thumbnails.
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Here is my performance on the first GPU - as you can see my FPS is at 30 - not bad for crysis.
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And now for the second GPU - 27.4 a grand total difference of about 3FPS that can be considered normal.
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Now we go somewhat across (somewhat evenly) graphics cards/two monitors - - 18.2 FPS with an explosion
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And for some reason I felt like spanning across four monitors - this time at 23.2FPS with an explosion.
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Is this meant to be definitive that windows 7 has addressed the issue of 3D applications spanning multiple graphics cards? Nah, it's just a test. Take it how you will - I found it interesting.

[jak3676]

Thx for the testing - I'm been looking at picking up a 4850x2 and hooking multiple monitors up to it. But I keep seeing problems withe multi-monitor/multi-gpu solutions. Of course there are still threads that come up about it not working correctly too. If I do it, I'll be on Win7 as well - probably time to just buy the card and find out.

[falsfire3401]

Hmm interesting.

I recently upgraded my 9600GSO to a 260GTX I noticed that on my 2nd LCD, even in windows, the picture is a little bit 'fuzzed' now at the same resolution and refresh rate...it's something to do with the new card.

Performance upgrade was huge, I get 40-70 FPS on my main wow client now as opposed to 18-28 I had before (slaves are capped at 15fps), but I'm a bit upset by the fact that everything is a *teency* bit fuzzy on the 2nd LCD now...

[alcattle]

try swapping the monitor cables, making sure both are tight