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Discussion Starter · #1 ·
Hello All,

I know its almost expected to have issues with something such as Eyefinity, although id like to find a solution here.

Yesterday i finally got my last monitor to run Eyefinity. I have 3 X 1920 X 1200 resolution monitors (Total is 5760 X 1200) My performance has dropped significantly in BF3 and few others. Before Eyefinity i was running BF3 on Ultra at 70 FPS, now i cant run it on Ultra, im forced to used High/Med settings.

I'm currently running with 2x HD 6950's CF, i was assuming that this tripled resolution would now require more GPU power? In this case i was looking into CF 7970's.. Would this be the answer to my performance decrease after Eyefinity?

Here is my System specs.. maybe i need to upgrade elsewhere as well?

Resolution: 5760 X 1200
Intel Core i7 920
6GB DDR3
1000W PSU
2X CF HD Sapphire 6950's
120 GB SSD + 1 TB HDD

 

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Hello mtb88

You would definitely benefit from newer cards. However, the fact is that your processor will be a bottleneck. If you want to run eyefinity, you will need an overclocked processor that is atleast 4.2-4.5 Ghz in order to properly utilize your new GPUs. If you use MSI Afterburner overlay and take a look at GPU usage, you will probably find that it rarely hits 99% which signifies that both GPUs are fully tasked with work. This is due to the fact that the CPU is not fast enough at sending packets to the GPU thereby creating a bottleneck.

I know this is a slight oversimplification but you should get the big picture.

My suggestion would be to first get an Ivy Bridge or a Sandy Bridge processor and overclock it.
If you don't see a decent performance increase then you need to start looking at new GPUs as well.

Thank you
 

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When you're talking a 5760 x 1200 setup, you need a whole system revamp, when you get better GPU's your current CPU is going to bottleneck them. You're going to need a 3770k w/ a 4.5Ghz+ clock and a few 7970's (or switch to Nvidia for an easier Nvidia Surround setup [which more games support]). Of course to run higher AA settings you'll want higher amounts of v-ram (3 or 4GB cards)
 

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Discussion Starter · #4 ·
Hello,

Thank you! I was considering a new build with an Ivy bridge i7, With this ill need a new MB/RAM. This will take some time for funds purposes but worth it in the end!
 

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Quote:
Originally Posted by .Cerberus View Post

Hello mtb88

You would definitely benefit from newer cards. However, the fact is that your processor will be a bottleneck. If you want to run eyefinity, you will need an overclocked processor that is atleast 4.2-4.5 Ghz in order to properly utilize your new GPUs. If you use MSI Afterburner overlay and take a look at GPU usage, you will probably find that it rarely hits 99% which signifies that both GPUs are fully tasked with work. This is due to the fact that the CPU is not fast enough at sending packets to the GPU thereby creating a bottleneck.

I know this is a slight oversimplification but you should get the big picture.

My suggestion would be to first get an Ivy Bridge or a Sandy Bridge processor and overclock it.
If you don't see a decent performance increase then you need to start looking at new GPUs as well.

Thank you
I'm sorry but this is totally incorrect. Resolution scale almost exclusively of GPU power and CPU power does not factor in to it. If a CPU can run a game maxed at 1080p then it can run it just as well at a higher resolution. All that is needed is more GPU grunt and VRAM.

So yes mtb88 crossfire 7970 is exacley what you want. Thous cards are as good as it gets currently in terms of Eyefinity performance (well there is always trifire but you get what I'm saying
wink.gif
)
 

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Whatever user that said a more powerful CPU is required to adequately feed multi-GPU at >2560x1600 resolutions is exactly right.
 

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CPU's still need to feed data to the GPU and they need to do it quickly otherwise the GPU will sit idle

I do agree that there is less stress on the CPU when gaming at a higher resolution but if you take a look at benchmarks with overclocked processors vs non-overclocked processors keeping the GPUs (2 or more) constant you will notice a performance increase. This may not be a factor to consider for a single GPU as you would basically a few frames difference but if you take a look here http://www.ocaholic.ch/xoops/html/modules/smartsection/item.php?itemid=836&page=7

You can see that the 3770K stock scores 58.5 fps vs a 920 @ 4Ghz that scores 52.6 fps on a single GPU. Unfortunately, I don't have any benchmarks that vary CPU settings with a dual GPU setup but from personal experience I can tell you that upgrading from an Intel 870 to a 2600K @ 4Ghz having 2 5870's gave me around 10-15 fps more in games like BC2
 

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Quote:
Originally Posted by .Cerberus View Post

CPU's still need to feed data to the GPU and they need to do it quickly otherwise the GPU will sit idle

I do agree that there is less stress on the CPU when gaming at a higher resolution but if you take a look at benchmarks with overclocked processors vs non-overclocked processors keeping the GPUs (2 or more) constant you will notice a performance increase. This may not be a factor to consider for a single GPU as you would basically a few frames difference but if you take a look here http://www.ocaholic.ch/xoops/html/modules/smartsection/item.php?itemid=836&page=7

You can see that the 3770K stock scores 58.5 fps vs a 920 @ 4Ghz that scores 52.6 fps on a single GPU. Unfortunately, I don't have any benchmarks that vary CPU settings with a dual GPU setup but from personal experience I can tell you that upgrading from an Intel 870 to a 2600K @ 4Ghz having 2 5870's gave me around 10-15 fps more in games like BC2
Yes there is a difference but it clearly is not solely due to the CPU speed as the stock clocked 920 and the 920 @ 4GHz are withing the margin of error and a Q6600 @ 3Gzh is shown to have better performance then a 920 @ 4GHz (in crysis 2). And for the record I did not say that CPU speed does not effect performance. I said that resolution is a completely GPU bound thing.

As an example I have to run catzilla at 560p (kitty) and disable 2 to get any kind of CPU bottlenecking going and even then its only when the FPS goes over 180. Step up that resolution to 720p and the GPU is back to being the bottleneck through out the run.
 

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Quote:
Originally Posted by Bit_reaper View Post

Yes there is a difference but it clearly is not solely due to the CPU speed as the stock clocked 920 and the 920 @ 4GHz are withing the margin of error and a Q6600 @ 3Gzh is shown to have better performance then a 920 @ 4GHz (in crysis 2). And for the record I did not say that CPU speed does not effect performance. I said that resolution is a completely GPU bound thing.

As an example I have to run catzilla at 560p (kitty) and disable 2 to get any kind of CPU bottlenecking going and even then its only when the FPS goes over 180. Step up that resolution to 720p and the GPU is back to being the bottleneck through out the run.
http://www.hardocp.com/article/2011/05/03/nvidia_3way_sli_amd_trifire_redux/2#.USPuWaU1b8s

read through it, you'll see that the CPU means quite a bit
thumb.gif
 

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Quote:
Originally Posted by appleg33k85 View Post

http://www.hardocp.com/article/2011/05/03/nvidia_3way_sli_amd_trifire_redux/2#.USPuWaU1b8s

read through it, you'll see that the CPU means quite a bit
thumb.gif
Again yes the CPU speed does make a difference. So does the platform and CPU architecture to. One major issue right out the door with that comparison is the x58 motherboard. I see no mention of the PCI-E slots and even most high end x58 mobos are pci-express 2.0 with the slots being x16 x16 x4 or x16 x8 x8 (when running 3 cards).

This suspicion is further enhanced as the 920 does much better in the trifire test that was done with 6990+6970. In the best case scenario the 920 actually beats the 2600k by 14.4% for some odd reason.

As the site that .Cerberus linked shows there is some times odd results that do not reflect the relative speed of the CPU's http://www.ocaholic.ch/xoops/html/modules/smartsection/item.php?itemid=836&page=7

If you are doing a proper test about the needed CPU/GPU ration then you should also include a down clocked results of the fastest system as a reference.

The CPU/GPU load balance differs widely from game to game so there is not single answers to how fast a CPU you need. The question is how fast of an CPU do you need in game X with settings Y for the GPU's to be the bottle neck all the time. That is not to say you need to be GPU limited all the time either. If you are gaming with 60Hz monitor you are not going to miss thous last 30FPS beyond 150 that you loose due to the limitation shifting off to the CPU.

But back to the issue at hand. The OP stated that he got good enough FPS form his two 6950's when running 1080p but after moving up to 5760 X 1200 he does not and is looking to do some upgrading. Yes having the 920 paired up with two 7970's is not always going to output the maximum possible FPS in all possible conditions but then again a 3960X will push out more FPS then a 3570k under some conditions. That does not mean you need a 3960X to run two 7970.

The OP needs more GPU power to run a higher resolution. Just getting two 7970 (or 7950's) will fix that. Sure a whole new system would be better but its not needed. When the 920 is no longer able to put out acceptable FPS then he can go out and spend money on a CPU/mobo upgrade. No point in doing it before Haswell and the OP can probably even wait for the Haswell prices come down.
 
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