GTX 570 3 Way SLI possibility?

[Russell_PC]

Hi Everyone, Im currently running 2 x GTX 570's with 1280MB of VRAM, Scaling at roughly 1.65% of a signal 570. Im Looking at buying another GTX 570 to run a 3 way sli setup, but with only 1.28GB of VRAM would I even see the differance? or would the lack of VRAM hold back any noticeable performance increase? I have a 1650x1080 monitor without 3D.

 

[mightymaxio]

You wouldn't see any difference maybe like .0001% increase with that resolution because by that point your entire bottleneck is your processor. 3-way and 4-way SLI are honestly only beneficial in extreme resolution settings such as 2560x1600 or using Nvidia Surround.

 

[Russell_PC]

Thanks for the reply

But lets say I was to get that resolution though? or 3D surround.
If then I were to buy a new 570, does my question about the 1.28gb VRAM in 3 way SLI still apply?
Would the 1.28gb of VRAM prevent any worthwhile increase that u'd want from 3 way SLI?
Or would it still be worth buying a 3rd GTX 570

Thank you

 

[mightymaxio]

1.28gb of vram is acceptable for most games although if you did surround you might lose maybe 2-3fps vs the 2gb or 3gb versions of the 570 because of the higher vram.

 

[Russell_PC]

So if I were to add a third GTX 570 I would still get a pretty decent performance boost as far as frames per second, minus only a few frames due to vram limitations? and the scaling would still be what you'd expect/want from a third GPU? so would you say, with a high resolution/surround, would it be worth buying a third 570?

 

[17seconds]

It all depends on your CPU. A fast Core i7 CPU will see actually a nice boost from adding a third 570. At 1080 resolution, your Vram is just about right. Adding more monitors will be affected by the Vram, but the additional speed of tri-SLI will make up for the lack of RAM.
http://www.guru3d.com/article/geforce-gtx-580-3-way-sli-review/

 

[inzone]

I am currently running three GTX 580 3gb video cards and in a game like BF3 you do see a difference in the fps. With all three in SLI I can get over 150 fps and when I run just two then it drops to around 100 fps and a single will pull around 60 fps. So yes in a game like BF3 at least in my setup it makes a difference. I have a 27" monitor at 1920x1080 and the game settings were at Ultra.

 

[inzone]

The cpu is an Intel 980x Extreme , 6 core.

 

[17seconds]

The cpu is an Intel 980x Extreme , 6 core.

Then get that 3rd card and crank 'er up!

 

[Russell_PC]

Hey thanks for replies
So my current CPU is the i5 2500K 3.3Ghz sandy bridge overclocked at 3.7Ghz. Matto's posted link for the 580 3xSLI review said that their i7 OC at 3.8ghz was struggling to keep up with the 3x580's. Does this mean my i5 4core 3.7 OC will put too much of a limitation on 3 GTX 570's? or will I still get good enough results to make it worht getting the 3rd 570? thanks again

 

[17seconds]

It all depends on what you are trying to accomplish. If you are just playing some games, then I don't think the third 570 will make the experience that much better. If you have specific slowdowns (unlikely) with your SLI setup, then I still think a tri-570 setup will be significantly faster with your CPU. Since the 570 is slower than the 580's in the review, that will afford you the benefit of slightly better scaling.

 

[Russell_PC]

Thanks matto,
Okay so I'm fairly certain now that I will buy a third GTX 570. I do play a lot of games including Crysis, Crysis 2 & BF3, which I know are very heavy on the vram. So just to clarify, if I buy this 3rd card and run 3 way SLI, I should still get pretty good scaling, even with 1.28gb of vram & an i5 2500k oc'd 3.7ghz, so long as I run 1080p, 3D, or mulit-mon setup.
If thats the case then this 3rd 570 sounds like a great idea
so shall I buy it.. ?

 

[17seconds]

Since you are getting down to decision time, I thought I would dig a little deeper. I'm seeing more of these types of results (below). It's a tough call, but definitely be aware that you need to overclock your CPU and that some games will scale better than others. It also depends on how much of a financial stretch it is for you to afford a third 570. Luckily, they are down below $300 now.

Test system:
Intel Core i7-2600K (Sandy Bridge) LGA 1155: 3.40-3.80 GHz, 8 MB L3 Cache
Overclocked to 4.00 GHz at 1.25 V

http://www.tomshardware.com/reviews/crossfire-sli-3-way-scaling,2865-10.html



Test system:
I7 920 @ 4.3 GHZ

"An Overall average of 34% faster than dual card is not bad considering we are also including in our average score titles that perform terribly due to PhysX or CPU bottleneck."
http://benchmarkextreme.com/Articles/GTX%20570/P1.html

 

[Russell_PC]

Thanks a heap, those charts are big help
its always good to see some figures,
Im going to assume that the 570's used in these tests were regular 1.25gb vram cards, and not 2gb cards.
If so then yes, that is the scaling and results I was hoping to see for a 3 way SLI setup, so it answers a lot of my questions, and definitely makes the 3rd card seem worth it.

And as for what I'm looking to accomplish,
2 things mainly,
Im hoping a 3rd card will give me a bit more future proofing?
and I want a decent increase in scaling, and fps, and those charts confirm that I should get that in higher end games. so Im happy with that.

From what these charts show me, it does look like 3 way sli will give me what I want, might have to OC my CPU a little more to say 4.0ghz to stop CPU bottlenecking but that isnt a problem.

oh & just curious:
With the AA turned up the scaling is better, so is it safe to say that the extra processing power counteracts the lack of vram, like u said earlier?

but yeah thanks again
Ive decided I will get another 570 and run 3 way sli
it seems like it'll give me what I was hoping for

cheers matto

 

[Russell_PC]

Best answer selected by Russell_PC.

 

[Mousemonkey]

This topic has been closed by Mousemonkey