Planning on sliing 2 gtx 970s with 4790k but the 4790k only has a max number of pcie lanes of 16?

[Wasard]

I was planning on getting a 4790k and two 970s for sli but I was looking around on ark and I noticed something, the 4790k has max number of PCIE lanes of 16. But I'm gonna be using two gpus, will I notice a performance hit for putting both of them on an 8x slot? Also what would happen if I were to put both of them on a 16x slot? Would one of them just not work?

[Yoinkerman]

with SLI it will be x8 x8

 

it works fine.

[TetraSky]

You won't notice any performances difference. Especially if it's PCI-E 3.0, so that 8x would equal 16x PCI-E 2.0

Last I cared to check, graphic cards barely even reached 8x PCI-E 2.0 speeds, so I think you'll be fine.

[Godlygamer23]

No, you won't notice any performance hit.

 

In regards to your second question, they would work using a PCIe riser. The lanes would still be split between the two GPUs. If you decide to go that route, make sure the riser offers supplemental power capabilities and that your power supply can handle it.

[crispybagel]

Nvidia SLI runs at x8 speed so it will be running fine. if you want 3 or 4way u need to get the x99 platform as the 5820, 5930 and 5960 has 32 and 40 PCI-e lanes.

[byalexandr]

I'd recommend two 390s instead. Crossfire scales much better than SLI and the 390 is a faster card anyway, both are in the same price range. And they'll run in 3.0 x8 x8, which is the equivalent of PCI-E 2.0 x16 x16 (so no performance loss at all).

[Moonzy]

Just now, Wasard said:

will I notice a performance hit for putting both of them on an 8x slot

close to none

source:

Spoiler

 

 

 

Just now, Wasard said:

what would happen if I were to put both of them on a 16x slot? Would one of them just not work?

to physically plug them in, you would need a splitter of some sort

and it will split the lanes into 8x 8x, so they would BOTH work

 

Just now, Wasard said:

I was planning on getting a 4790k and two 970s for sli

if you havent got even one 970, i suggest going with a single 980 Ti

because SLI pose issues that are not worth hassling with if you can get the same performance from a single card

not to mention you get more Vram (3.5gb vs 6gb)

[BlueCrazii]

I can reply to this because i have 2 970's and i say go with 1 980ti