Two 6990s for eyefinity

stereopsis

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Hello,

I have a couple of questions:

1) Is the purchase of 2 6990s a worthwhile investment for eyefinity? It would be a three monitor setup.

2) would the 2 6990s scale well? Are there issues with drivers?

3) I am still running a Gigabyte X48-DQ6 motherboard with a Q9550...will the two 6990s saturate this setup?

Thanks in advance for your responses.
 
Solution
Eyefinity should work on your platform but I think you need to consider a few things:

1. Avoid ultra high resolutions. ie don't expect 3 2560x1440(or 1600) to work effectively. 3 1920x1080 should work.
2. You will probably have to turn down/off eye candy. ie AA/AF/Ambient Occlusion etc.
3. Your amount of VRAM is important. 1.5Gb min.
4. You probably could get away with using a pair of 6950s or 6970s in crossfire and use the remainder of your budget to upgrade MB/CPU. This should balance things out.
5. You could try to OC CPU. This should help.
6. Check that you have enough juice on your PSU. VERY important.

Hope this helps some.

hunuok

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I think your motherboard and CPU will bottleneck those cards.

Also, Quad crossfire or Quad SLI has issues and has diminishing returns for the extra (ie 4th) GPU.

Tri crossfire or Tri SLI is the sweet spot IMO.

Here is an article that gives you a review of quad GPU performance:

http://www.hardocp.com/article/2011/05/19/quadgpu_performance_review_nvidia_vs_amd/

Here is an article that explains performance increases using upgraded CPU/motherboard setups:

http://www.hardocp.com/article/2011/05/03/nvidia_3way_sli_amd_trifire_redux/

 

stereopsis

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Thanks for that :)

Yeah 4gpus seems exessive, 3gpus scale better...apparently though 3 way crossfire is not as limited by cpu as 3 way sli which is good to know. i just wish I could actually figure out how 3 way crossfire would work with my platform...especially in eyefinity.
 

hunuok

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Eyefinity should work on your platform but I think you need to consider a few things:

1. Avoid ultra high resolutions. ie don't expect 3 2560x1440(or 1600) to work effectively. 3 1920x1080 should work.
2. You will probably have to turn down/off eye candy. ie AA/AF/Ambient Occlusion etc.
3. Your amount of VRAM is important. 1.5Gb min.
4. You probably could get away with using a pair of 6950s or 6970s in crossfire and use the remainder of your budget to upgrade MB/CPU. This should balance things out.
5. You could try to OC CPU. This should help.
6. Check that you have enough juice on your PSU. VERY important.

Hope this helps some.
 
Solution

stereopsis

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great response, thank you.

I want to do 3 x 1920 x1080, so that would be cool. Still considering tri fire - one 6990 and 6970. That should give me 6GB of Vram. I am planning on buying the corsair AX 1200 gold PSU so that should give enough juice. I am wondering about the platform though, should I get sandy bridge or wait for ivy since that is just around the corner?
 

hunuok

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That should give me 6GB of Vram.

Unfortunately, the the total amount of VRAM is NOT the sum of the memory on your VGAs (ie 2+2+2Gb).

The max you have available would be 2Gb, the amount PER GPU.

The Corsair AX1200 is a beast.

As for Sandy or Ivy, it depends on how long you are willing to wait for Ivy.

There should be an update Sandy i72700K due soon.

I believe Ivy is due in Q1 2012 and Sandy E in Q4 2011.

Sandy E will be expensive. Unlocked i73930K $583 and i73960X $999. Source:

http://www.anandtech.com/show/4626/info-on-sandy-bridgee-pricing
 

stereopsis

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I can do the upgrade in parts...the current platform, although not perfect is not bad, and I am thinking ivy will have more to offer than sandy. Although that could also be said about the upcoming radeon 7000 series :) Deo you really think that there would be a considerable cpu bottleneck occurring even at higher resolutions on the q9550?
 
The MOBO supports only 2-way crossfire / SLI (check your manual to see if it supports CF or SLI or maybe both)
your CPU is just fine and will do the job whether it's 2 HD 6990s or 3-way HD 6950s.
just a little overclock a bit higher and you're good to go.
but my advice is to wait until you upgrade your whole rig, and better wait for AMD HD 7K series, the first GPU is to be released December 6.

what i know so far about HD 7K is they are equipped with new XDR2 rambus memory which is twice faster than GDDR5, new 28nm process = less power consumption & less heat besides the 1 GHz GPU frequency, a single HD 7950 is said to be better than HD 6990.
 

stereopsis

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Yes this is true, the 7000 series should be awesome, I checked out the specs as well...I was wondering about price/performance ratio though, are they going to be considerably more expensive when they are released (my guess is they probably are)?

Thanks for your input...

and yes the mobo only supports 2 way crossfire, that's why I was thinking 6990 + 6970...