Can an I7-870 @4.1ghz bottleneck 2x GTX 980's in SLI?

[Sd4Insanity]

Hello everyone! I hate to ask a seemingly redundant question, but the TH forums always give the most definitive answers, so I figure a little clarification here will go the distance. Having said that, I'm attempting to hit 60hz@ 4k. Here's my setup:

I7-870 OC@ 4.1GHZ on H20
Asus P7P55D-E Pro mobo
16GB Kingston Hyper X DDR3 Ram
EVGA GTX 980 FTW OC to 1500mhz

Before I rush out to buy either another EVGA GTX 980 FTW, OR an I7-5930K/Asus X99 Sabretooth Mobo, here's the question:
Can my setup handle 2x EVGA GTX 980 FTW's in x8/x8 SLI and perform fluently at 60hz@4k resolution, or will the CPU create a processing bottleneck?
I've scoured the interwebs, and consulted several supposed "bottleneck" calculator websites, but none of them give me any indication of the performance hit (If any), that I would take by using two incredibly powerful GPU's with my current setup. They all seem to indicate the need for a second GPU, but I'm concerned that it won't run to it's full potential. The I7-870 and P55 chipset are rated at 16 lanes of PCI-e 2.0. I guess I'm wondering where my money would best be spent (new cpu/mobo, or expansion of my existing setup). My thanks to all who take the time to respond in a thoughtful manner. You are the very fabric of this forum!!!

 

[cdrkf]

It's hard to say for sure- it depends on a lot of what specific game you want to play. Games that push the gpu more than anything else will benefit from the extra gpu, other games that are poorly threaded may well be held back by cpu performance, but then the 4k settings will push the load heavily towards the gpu.

I think the biggest problem in answering this is almost all SLI reviews are done on the most powerful processors available 'to avoid bottlenecks', however without some testing done on different machines there's never any point of reference to compare against. It might be worth looking for SLI / Crossfire benchmarks performed with AMD FX processors. As I understand it soemthing like an FX 8350 should be similar in performance to your first gen i7 so would make a reasonable comparison.

As for the PCI-e 2 lanes, they did a recent test using the Titan X to check what impact the PCIe bandwidth had on fps- the answer was unless you restrict a modern card to PCIe vs 1 then it had virtually no impact so you should be ok on that front at least.

 

[OpTic_G1BBY]

! 980ti no it wont bottleneck it, 2 980ti's yes it will bottleneck it. My advice would be unless you are playing 4k or 1440p 144hz then go with 2 GTX 980 no ti's and get yourself a 4790k and a z97 mobo.