Will PCIe 3.0 x8 bottleneck SLI 680s?

[SD2k]

Hi guys,

I've looked around all over the place for this info and it's possible that no-one knows, but all I've managed to find is info on quad-SLI or single GPU.

I'm trying to decide between motherboards, with the two options being:

• Gigabyte Z77X-UD5H
  Gigabyte Z77-G1-Sniper 3

The main difference I'm interested in is the x16/x16 PCIe 3 capabilities of the Sniper, but it's also an extra £120

Would two 680s in SLI be bottlenecked by PCIe x16?
(Also while I'm here, does anyone know if the Sniper would be noticeably better for CPU overclocking than the UD5H?)

Cheers

 

[Cythx]

I don't think you'd lose more than a few % in performance in going from x16 PCI 3 to x8 PCI 3.

 

[Rusty0611]

As x8 PCI-E 3.0 is the same as x16 PCI-E 2.0 - no you shouldn't see a bottleneck.

 

[Cythx]

You might also be interested in this

http://forums.overclockers.co.uk/showthread.php?t=18393640

 

[mmj_uk]

Only if you run at super high resolutions (2-3 screen) and VRAM does become an issue.

 

[Clav]

As mentioned above, x8 pcie3 is the same as x16 pcie2 bandwidth. There should be no issues running x8,x8 pcie3. I don't see a problem with even running x4,x4 with pcie3 as that is perfectly acceptible bandwidth for current cards.

 

[Zeed]

this is how you sell stuff people dont need see ??
You just tell them its beter and add +1 to version and many people will run and buy it.
It was like that when PCIe came out. Same cards ware available for AGP and PCIe but they said PCIe was faster and people changed motherboards with same cards that they could used on their AGP motherboards.....

 

[Cythx]

PCIe 3 actually shows significant benefits for people who run games on multiple monitors, even people who use single monitor 2560x1440 or higher.

 

[Soundood]

no

 

[SD2k]

Awesome, cheers guys - I'm playing at 1080p 120Hz so not high resolution just high framerate, sounds like the difference will be minimal.

 

[Rusty0611]

You're going to get ridiculously good performance. I want 2 680s

 

[SD2k]

Me too, it hasn't happened yet setting up a watercooling loop first!

 

[andybird123]

As mentioned above, x8 pcie3 is the same as x16 pcie2 bandwidth. There should be no issues running x8,x8 pcie3. I don't see a problem with even running x4,x4 with pcie3 as that is perfectly acceptible bandwidth for current cards.

x8 pcie3 should be fine... however there are some slides kicking about of 16x/8x/8x pcie3 and 16x/8x/8x on pcie 2 showing a substantial difference, so I would think pcie3 4x will start to bottleneck an SLI rig