Pci-e Gen 2 vs Gen 3 GTX 1070 Performance

[JHawks]

So I just finished my custom pc build mk. 1. When I first booted up everything seemed fine and normal but then when I went to play a video the playback was very messed up, and the audio was teribble.

After a brief poke around I suspected it would be the pcie riser cable (which is disappointing as I splashed out on a somewhat more expensive one to avoid problems) . I reseated it, checked for debris etc, then it just wouldn't display at all. (Using HDMI out)

I switched to onboard graphics, tinkered and switched all the pcie slots to gen 2, which did the trick, everything working fine. This was strange as it seemed to auto detect as gen 3.

My question is twofold; Any ideas what could cause this? Secondly Will this affect gpu performance? I've done some research and most of the posts suggest there's not really much to worry about, but all the posts I've found are also quite old and was wondering if newer graphics cards (gtx 1070) are any closer to the limits of pcie gen 2 than a few years ago?

I see now that that is quite waffley.

TL;DR - Is setting my pcie slot to gen 2 going to affect the performance of a gtx 1070? Why would setting a gen 3 riser cable to gen 2 make it work?

 

[maxalge]

So I just finished my custom pc build mk. 1. When I first booted up everything seemed fine and normal but then when I went to play a video the playback was very messed up, and the audio was teribble.

After a brief poke around I suspected it would be the pcie riser cable (which is disappointing as I splashed out on a somewhat more expensive one to avoid problems) . I reseated it, checked for debris etc, then it just wouldn't display at all. (Using HDMI out)

I switched to onboard graphics, tinkered and switched all the pcie slots to gen 2, which did the trick, everything working fine. This was strange as it seemed to auto detect as gen 3.

My question is twofold; Any ideas what could cause this? Secondly Will this affect gpu performance? I've done some research and most of the posts suggest there's not really much to worry about, but all the posts I've found are also quite old and was wondering if newer graphics cards (gtx 1070) are any closer to the limits of pcie gen 2 than a few years ago?

I see now that that is quite waffley.

TL;DR - Is setting my pcie slot to gen 2 going to affect the performance of a gtx 1070? Why would setting a gen 3 riser cable to gen 2 make it work?

depends, if its full 2.0 x16 then no, you are loosing nothing

 

[SkyNetRising]

Did you try without that riser cable?

Also - please post full specs of your hardware.

 

[leo2kp]

To answer some of your question, I'm running a GTX 1080 over PCI-E 2.0. Benchmarks are right where they should be and performance is fabulous. As far as bandwidth is concerned, you're fine running over PCI-E 2.0 X16.

 

[JHawks]

Excellent! Yeah it's def running at x16, just gen 2. It works fine straight in the slot, so I'm 99% certain the problem was the cable. System specs are: i7 4770k, asus z97 wifi pro, 16gb 2133 ram, bequiet 650w psu, gtx 1070 fe. I was worried coz I had to cut a hole for the gpu outputs and really didn't want to have to fill it and cut another/lose performance for the sake of aesthetics!