So right now there's a couple "steal of a deal" scenarios with the hd 5970's. I have a 5970 with my current set up which I will get to in a minute. My question is if I purchased another hd 5970 and crossfired it with my current set up what are the pros and cons of doing so?
CPU:i7-860 (bios factory overclocked to 3.3)
PSU: corsair 850tx
Ram: 8GB GSkill RipJaws Clocked at 1533
MOBO: Asus P7P55 e pro
HDD: Intel x-25m SSD G2
GPU: ASUS HD5970
I have heard in the past that crossfiring this type of card on my set up will oversaturate the two pcie lanes to the point that I may actually see a decrease in performance because of the 8x/8x lanes when in crossfire. If there are any links on the degredation of performance with high end cardds in 8x/8x I will be more than happy to look for them...Google doesn't really help unless I'm just searching wrong? I have also heard that if I go crossfire with another 5970 my processor would have to be overclocked to close to 4 ghz in order for it not to bottleneck the graphics cards performance. I am also interested in hearing any other opinions as to what I might do as opposed to this idea, given this idea isn't a good one. Thanks for your answers in advance!
With An Older Generation Card Like The 5970 And A System With Those Spec There Shouldnt Be Any Issues, x8/x8 WIll Make No Noticable Differance. The Only Thing Id Worry About Is If You Have The PSU Power To Handle The Cards, The Proper Spacing Betwwn The Cards And Space.
The Only "Con" Is There Is A Few Games Including Newer Ones That Dont Scale Well On Multi-Card Setups And Some That Dont At-All, Thus The General Reason I Avoid Multicard Setups Alltogather, I Just Get The Most Powerfull Single Card I Can Afford. Personally I Dont Care About Frame Rates As Long As The Game Plays Smoothly At The Settings I Desire, I Dont Care If Its 60 Or 160FPS.
I don't have a link handy but Toms has done several stories on the preformance gains from 8x to 16x PCIe and found that even with most powerfull cars available today an 8x PCIe 2.0 slot won't bottle neck the card.
From the THG Sandy Bridge-E And X79 Express review, page "Crysis 2 In SLI " - "There’s nothing to indicate that two PCI Express x16 slots are of any benefit to our GeForce GTX 580 cards in SLI compared to Z68’s two PCI Express x8 slots, though."
Okay, so you have all confirmed what I was hoping...So what about my processor and psu? Are they beefy enough to handle a quadfire set up? I had read that I really do need to get my processor past 4ghz in order for it not to bottleneck. Better safe than sorry; anyone who can add their two cents to the first reply about my i7-860 being able to do the job, please let me know...And I'm guessing a good 1000watt psu would be sufficient if my current 850 is too little?
I would suggest O.C.ing.Maybe not 4ghz but somewhere around 3.6ghz+ would be ideal.If/when you get the card you should run some test at the stock clocks of the i7 then at your current O.C. and another if you can reach a higher O.C.Look at how much performance gain the GPU's see and then you'll know if your current speed is bottlenecking.
Two 5970's in crossfire should consume roughly 600 watts.You should be ok with your current PSU even with an O.C.