I am 6 pages late to the discussion but I will offer my analysis. It is a little long and there is a logic flow. So, follow the steps through to the end with some patience:
(I) First off, one fact
A stock Phenom II X6 1100T is sufficient to run GTX 570 SLI at full potential (at 2560x1600 with high IQ).
(II) CPU consideration
. stock Phenom II X4 965 performs similarly to X6 1100T because the 2 additional cores do not make a 'significant' difference in gaming
. stock Phenom II X4 965 at 3.4GHz is comparable to stock Phenom II X6 1100T at stock 3.2GHz because the 0.2MHz is insignificant.
So, we can safely say that ''a stock Phenom II X4 965 is sufficient to run GTX570 SLI at full potential at 2560x1600 with high IQ.
(III) Resolution consideration
Now, it is easier to conclude if the OP's friend's resolution is 2560x1600.
But for the sake of investigation, assume OP's friend's resolution is 1920x1080/1200.
Then, the Q becomes a graphical comparison between:
: GTX570 SLI at 2560x1600
: GTX580 SLI at 1920x1080
poses no problem for a stock Phenom II X4 965. How about B
is obviously putting more load onto the CPU.
Using guru3d's framerates for 7 games tested, I averaged the framerate decrease when going from 1920x1200 to 2560x1600:-
1. for GTX570 SLI: (28+29+23+28+44+16+28)/7 = 28%
2. for GTX580 SLI: (29+20+20+21+40+ 5+22)/7 = 22%
Take a middle number of 25%
(IV) GPU consideration
At 1920x1200, GTX580 SLI is about 10% faster (more framerates) than GTX570 SLI
(averaging data of the 7 games here:http://www.guru3d.com/article/geforc...0-sli-review/5
(V) Putting (III) and (IV) together
Things do not go linear but just as a rough estimate, let's say: B
gives about 35% more framerates than A
(25% coming from a lower resolution and 10% coming from a stronger pair of GPUs).
Then, the Q becomes: Is a stock Phenom II X4 965 sufficient to run GTX580 SLI at 1920x1200 (which is 35% graphically more than GTX570 SLI at 2560x1600 with high IQ) at full potential?
(VI) For this Q, we turn to this review
This shows that, for the averave of 19 games, GTX570 3-way SLI is about 34% faster than GTX570 2-way SLI, at 2560x1600.
: GTX570 3-way SLI at 2560x1600
is graphically 34% higher than A
is also graphically 35% higher than A
Then, the Q becomes: Is a stock Phenom II X4 965 sufficient to run GTX570 3-way SLI at 2560x1600 at full potential with high IQ.
(This Q is just the same as asking: Is a stock Phenom II X4 965 sufficient to run GTX580 SLI at 1920x1200 at full potential with high IQ
The final answer is: Yes and No
'Everything below Cryostasis in the above graph is heavily GPU dependent and a stock Phenom II X6 1100T is sufficient even in TRI SLI mode.
This means, stock Phenom II X4 965 can run GTX580 SLI at 1920x1200 at full potential for games like Cryostasis, Battleforge, Stalker Cop, Napoleon Total War, Lost Planet, Metro 2033, Alien vs Predator.
In some GPU heavy titles TRI SLI exhibits significant CPU bottleneck even up to 4.2 GHZ CPU frequency. In the above graph all the games above the "average" bar fall in this category.
This means, Phenom II X4 965 experiences significant bottleneck for games like Resident Evil 5, Hawx2, Crysis Warhead, Mafia 2(no Physx), FarCry 2, Lost Planet 2, Necrovision
(I did this very late at night...excuse any mistake made)Edited by windfire - 3/1/11 at 10:08pm