Help with Motherboard

[SeriousTyro]

I am helping my girlfriend build a rig octance, GPU renderer.

I already bought: https://www.asus.com/us/Motherboards/ROG-STRIX-Z270F-GAMING/overview/

I have seen many images of the motherboard supporting 2 GPUs but am wondering if it could fit another and would there be enough PCIe lanes?

The plan for the build is to get an initial 1080Ti and possibly another in the future.

Octane is able to use scale with multiple GPUs of different types, so I was going to also include a 670 that I have gathering dust.

Would this motherboard support 3 GPUs: x2 1080Ti & x1 670 or should I return the motherboard and opt for another motherboard for future-proofing in the sense I want add more GPUs?

[Ethan_NLHW]

The Z270 chipset itself gives you 14 PCIe lanes in conjunction with however many are on the processor you choose. As long as you're not running them in SLI it should be able to use three GPU's, as that board is only capable of two way SLI.

[Terryv]

57 minutes ago, Ethan_JL said:

The Z270 chipset itself gives you 14 PCIe lanes in conjunction with however many are on the processor you choose. As long as you're not running them in SLI it should be able to use three GPU's, as that board is only capable of two way SLI.

Those 14 lanes provided by the chipset are still limited by x4 when communicating to the CPU. This board will probably work with 3 GPU'S (x8, x8, x4 config) check your manual to make sure.

[SeriousTyro]

Thanks.

 

I think I can do a x8, x8, x4 config.

 

 

http://dlcdnet.asus.com/pub/ASUS/mb/LGA1151/STRIX_Z270F_GAMING/E12193_STRIX_Z270F_GAMING_UM_V2_WEB.pdf?_ga=2.13433207.1774186167.1506715735-702477231.1506715735

[SeriousTyro]

Nevermind, I got a i7-7700k and it only has 16 PCIe lanes.

 

I only be able to use 2 GPUs: x8 and x8

[Ethan_NLHW]

20 hours ago, Terryv said:

Those 14 lanes provided by the chipset are still limited by x4 when communicating to the CPU. This board will probably work with 3 GPU'S (x8, x8, x4 config) check your manual to make sure.

Thank you for clarifying. Left that part out.

[Terryv]

18 hours ago, SeriousTyro said:

Nevermind, I got a i7-7700k and it only has 16 PCIe lanes.

 

I only be able to use 2 GPUs: x8 and x8

The 7700k actually has 20 lanes  4 are dedicated to the chipset and the rest are open to expansion slots.

 

While you can use the chipset lanes for a GPU, these lanes also handle all the i/o as well. This GPU might be bandwidth starved compared to the others.