3x 30" Portrait 6970 CF Eyefinity vs 580 SLI Surround Showdown

[Callsign_Vega]

Test setup:

580's SLI lightly OC'd 800/1600 running driver 263.09. 6970's CF lightly OC'd 950/1420 running driver 10.12a.

All Benchmarks are bezel corrected (besides 5760x1200) and have 2x AA. ZR30w's have their plastic bezels removed and monitors clamped together to get the smallest vertical gap between screens.

i7 920 D0 @ 4.55 GHz
6GB DDR3
Intel SSD
Asus Xonar Essence STX Sound
3x 30" HP ZR30w's in Portrait





I don't have any fancy graphics for the benchmark numbers, so a spreadsheet view will have to do. Going from left to right, the numbers would mean average / min / max. ^ = nVidia DX9 AFR portrait FPS limit bug of 39/40. More on that later.
All in game settings are maxed unless otherwise stated. AF16x is forced in both drivers as well as disabling "optimization" driver settings which only gain you 1-2% performance anyways. Sorry 5760x1200 users, the 580 benchmarks went flawlessly as you can natively select that resolution in Surround but AMD wouldn't let me set that no matter what I did. Only Heaven 2.1 custom resolution worked. Manually editing the other games files didn't work and gave D3D errors etc. I tried registry edits to get 1920x1200, but that wouldn't work in Eyefinity. The last resort was going to edit EDID files but that's a bit involved and not worth it for a resolution I will never use. Blame AMD's wonderful driver team for not allowing a basic 1920x1200 16:10 resolution on a 16:10 30", wtf?




* = 580 memory limit reached as viewed per MSI Afterburner.

The breakdown:

Heaven 2.1 DX 11 - 6970 CF comes out above the 580's here. The 580's run into memory problems. But even at the lower resolution where memory isn't as big of an issue, the 6970's still win out. Crossfire scaling is around 85%.

Resident Evil 5 - 6970's win by a fair margin.

Eve Online - Even though SLI does work in Windowed mode, I pulled in a lower number with the 580's than I did with the 6970's in which Windowed mode only works single card. Win 6970.

DCS:A10C Beta / Medium in game settings - Mixed results here, the 580's ran into serious memory issues.

Aliens vs. Predators DX11 benchmark - Clear winner for the 580's.

Hawx 2 benchmark - In landscape you can see the 580's trump the 6970's. The 6970's win in portrait mode because of the DX9 AFR portrait bug on the 580's.

Battlefield: Bad Company 2 - One of my favorite games. The 580's win here but just slightly. You can see 95+% crossfire scaling.

World of Warcraft DX 11 mode - Clear winner in the 6970's.

Rise of Flight - Favor to the 6970's.

Left 4 Dead 2 - 6970's win.

Batman - Guess what 580's? DX9 AFR bug, yet again. The 6970's do well with virtually 100% crossfire scaling, yet if the 580's portrait bug wasn't there I believe it would have won out in portrait mode just like it did in landscape.

Metro 2033 - The 580's just edge out the 6970's here in portrait mode.

MS: FSX DX10 - Crossfire didn't seem to be kicking in here much for some reason, giving the nod to the 580's.

Lost Planet 2 - Favor: 580's.

There's no way around the nVidia Surround DX9 AFR portrait mode FPS limit bug that I could find. You also cannot enable triple buffering via D3DOverider in AFR, only SFR mode. That poses a problem because in order to eliminate screen tearing, you need VSync. In order to get VSync without tremendous input lag you need triple buffering. You see where that is going.

Without Vsync on, both the nVidia and AMD camps both get horrible screen tearing. This occurs no matter the FPS. Above 60, below 60, it doesn't matter. Some games automatically enforce triple buffering to limit the input lag, but for the ones that don't you need D3DOverider/ATI Tray Tools etc.

Ease of setup - The 580's were much less painful to setup and get running in SLI. Run 3x DVI-D cables. The displays just "work" like they are suppose to with DVI-D, even with the 3x 25 foot cables I use to get the signals from one room, through the wall into the computer area. Not having to deal with the sound and heat of a computer in your immediate area is so sweet. Install the drivers, setup the Surround resolution, bam your done. The 580's also over clock real easy in SLI and didn't produce many problems. AMD has a bad driver stigma because their drivers, well suck!
Recap:

580's would be much more competitive in DX9 portrait games if nVidia would sort their drivers and fix the FPS limit bug. Too bad most games are still DX9 as the bug doesn't exist when using DX10/11 as you can see in BF:BC2 numbers. If nVidia doesn't fix their drivers, as more games leave DX9 behind this will become less important.
580's 1.5GB memory limits its performance at such a high resolution. At 5760x1200 and below it isn't as much of a factor.
SLI works in windowed mode, CF does not.
SLI works in virtually every game, CF does not in a select few.
2GB VRAM means 6970's can run the 3x 30" resolutions at 4x AA +.
Crossfire scaling is quite good. 90-100% gains normal by adding a second card.
Display port sucks.
Noise levels and heat output are similar for both setups. At 100% GPU load in my super air cooled case the GPU temps average 65-70 deg C max for both setups. The 6970's are noticeably louder and I confirmed this with using a dB meter.
In order to save a nickel, AMD decided to make one of the DVI ports single link only!
Vsync on 580's Surround is perfect using 3x DVI-D cables. Vsync on with 6970's present a large problem in Eyefinity as you are mixing Display port/DVI-D signals and a single permanent obvious screen tear will always be present. The only way around this is to wait for "Eyefinity 6" edition 6970's or get the 3-DP 6990 when they are released.

Major pitfalls with 580's 3x 30" Surround: 1.5GB VRAM, DX9 Portrait AFR FPS limit.
Major pitfalls with 6970's 3x 30" Eyefinity: Display port, mixed display connectivity screen tear, AMD drivers.

I have been thinking of whether or not trying out the 6990 cards in CF for four GPU's if they launch with 4 GB (2GB frame buffers). This does pose some problems. Quad CF is notorious for having issues and increasing input lag because of all of the buffer flipping. Single GPU games like Rise of Flight and Eve windowed performance would actually decrease as you would only be using one of the four GPU's which would be at a lower clock. Some games like DCS-A10C I'd run into CPU limiting way before 4 GPU's are pushed to max. Besides Batman, with the 6970 CF setup I can run minimum 60 FPS already with some room to breathe and lock the FPS there. I don't even think a GTX 595 would compete unless they came out with 6GB cards. Yes, 6GB would be needed (3GB frame buffer) per card or it would just crash like the 580's when it runs out of VRAM.

If anyone has any good ideas on how to get the "custom" 5760x1200 resolution to work with the 6970's, I am all ears and would finish the benchmarks for that resolution.

I will try and update these benchmarks when new drivers are released by both sides.

Please let me know if you have any questions.