GTX 1080 PCIE 3.0 x8 Bottleneck?

[bboysania]

Hi Linustechtips,

 

I am building a new gaming rig 

 

(mobo: asus maximus viii gene, cpu: i6700k, gpu: asus strix gtx 1080, cpu cooler: noctua nh-d14, psu: evga 650 supernova g2, mATX case from Nanoxia)

 

so straight to the question:

 

"The cpu cooler is covering the pcie x16 slot, i cannot insert the GPU without it touching the heatsink of the cooler, i am thinking to insert the graphics card into the other pcie x8 slot and have my mind calm, but will the pcie 3.0 x8 slot (~ 8Gb/s - info from wiki) bottleneck my brand new Pascal GPU (~ 10Gb/s - info from Nvidia website) according to gameplay FPS etc? And if yes how much?

 

I tried to find the answer on internet but without luck to find the information i am seeking. If someone found something about this particular question, the links are very appreciated. 

 

[McHox]

not at all,will be fine

[Uzukami]

No it won't have any effect.

[bboysania]

Did anyone already test it? I mean real-life scenario, or all the answers is a theory, based on the previous gen. GPUs? Can someone with the experience of having the Pascal GPU, I don't mind the founders edition, confirm it? Thank you guys in advance.

[Megazero]

12 hours ago, bboysania said:

Hi Linustechtips,

 

I am building a new gaming rig 

 

(mobo: asus maximus viii gene, cpu: i6700k, gpu: asus strix gtx 1080, cpu cooler: noctua nh-d14, psu: evga 650 supernova g2, mATX case from Nanoxia)

 

so straight to the question:

 

"The cpu cooler is covering the pcie x16 slot, i cannot insert the GPU without it touching the heatsink of the cooler, i am thinking to insert the graphics card into the other pcie x8 slot and have my mind calm, but will the pcie 3.0 x8 slot (~ 8Gb/s - info from wiki) bottleneck my brand new Pascal GPU (~ 10Gb/s - info from Nvidia website) according to gameplay FPS etc? And if yes how much?

 

I tried to find the answer on internet but without luck to find the information i am seeking. If someone found something about this particular question, the links are very appreciated. 

 

1. The Maximus VIII Gene have 2 PCIE x16 slot, or to be more specific it will become x8/x8 if you plug 2 GPU on both of them, else if you only plug your GPU in 1 of them that slot you plug in should run at x16 if I'm correct

2. As far as PCIE speed vs performance goes, it doenst really matter that much. You can read about it here: https://www.pugetsystems.com/labs/articles/Impact-of-PCI-E-Speed-on-Gaming-Performance-518/ . I dont think anyone have specifically try a 1080 with a PCIE x8, since ppl with a 1080 usually have a beefy mobo as well so...

[HybridCraft]

I hate to beat a dead horse, but I'm reallllly curious about the effects of PCIe(3.0) x8 with the gtx1080.  The Z170 with skylake gives a max of 20(16+4) PCIe lanes.  I would like to use two m.2 ssds in raid 0 (uses 8 lanes), however that forces the gtx 1080 into x8 mode.  I've scoured the interwebs for benchmarks with the 1080 in a x8 and have not been able to find it.  I'm aware of benchmarks for titan and 980ti, but neither of these can clear the 8gb/sec, but the 1080 in theory, can.

 

I would be extremely grateful if anyone here is able to show a comparison for x8 vs x16 with the gtx 1080.

 

Cheers,

[bboysania]

I am waiting at the moment for my pre-ordered Asus gtx 1080 strix. I will post the results as soon as i have the card, unless someone else does it before me. I would also appreciate if someone posts his results too. To create more objective view on this theme.

[Lays]

On 6/10/2016 at 5:14 PM, HybridCraft said:

I hate to beat a dead horse, but I'm reallllly curious about the effects of PCIe(3.0) x8 with the gtx1080.  The Z170 with skylake gives a max of 20(16+4) PCIe lanes.  I would like to use two m.2 ssds in raid 0 (uses 8 lanes), however that forces the gtx 1080 into x8 mode.  I've scoured the interwebs for benchmarks with the 1080 in a x8 and have not been able to find it.  I'm aware of benchmarks for titan and 980ti, but neither of these can clear the 8gb/sec, but the 1080 in theory, can.

 

I would be extremely grateful if anyone here is able to show a comparison for x8 vs x16 with the gtx 1080.

 

Cheers,

It won't force the card into 16x.

 

The m.2 ssds should/will run off the chipset.  The gpu will run off the CPU lanes. 

 

The cpu has 16 lanes, the chipset has 20. 

[Gmanparty]

I just tried it using z170 pro gaming with 6700k cup and GTX 1080 FE. Both running at pice 3.0 and card's fan set at 100% to eliminate different gpu boost. 

 

X16 benchmark results first pic. 

 

X8 benchmark result second pic

 

same thing!

 

 

[bboysania]

Thank you Gmanparty, you solved the problem. Looks like it has no actual effect on the performance.

[Gmanparty]

Yeah No effect at all. But as a tip. Run ur card fan at 60-70% rpm during gaming to get better gpu boost. Benchmark showing 1-2% improvement. Haha. 

[HybridCraft]

On 6/14/2016 at 8:52 AM, Gmanparty said:

I just tried it using z170 pro gaming with 6700k cup and GTX 1080 FE. Both running at pice 3.0 and card's fan set at 100% to eliminate different gpu boost. 

 

X16 benchmark results first pic. 

 

X8 benchmark result second pic

 

same thing!

 

 

Thanks Gman!!!! I really appreciate you taking the time to benchmark it.

 

Cheers!

[bboysania]

Hey everyone, here is a further update on the topic! Check the link below:

 

 

[LogicsAndVr]

I have a Asus Z170 Pro Gaming and a Asus GTX 1080 FE, and GPU-Z reports x8, not x16. I have it in the top PCI-E port. How do I change it to x16?

[Glenwing]

6 minutes ago, LogicsAndVr said:

I have a Asus Z170 Pro Gaming and a Asus GTX 1080 FE, and GPU-Z reports x8, not x16. I have it in the top PCI-E port. How do I change it to x16?

Don't hijack other people's threads please.