Confused about PCIe slots and multiple GPUs

[json111]

Hi all,

I'm pretty new to mining. I was thinking of setting up a hybrid mining/workstation using two GTX 1060 GPUs. Most of the motherboards I'm looking at (like this one: https://www.msi.com/Motherboard/X370-GAMING-PLUS/Specification) feature two full-sized x16 PCIe connections, but the motherboard specs say that they function as either x16 (if using one GPU) or x8/x8 (if using two GPUs). Does not being able to run them at x16/x16 matter for hash rates? If not then could I potentially use another Gen2 slot for another GPU (even though it's an x4)?

Let me know if this makes any sense.

[gotminer]

Hi all,

I'm pretty new to mining. I was thinking of setting up a hybrid mining/workstation using two GTX 1060 GPUs. Most of the motherboards I'm looking at (like this one: https://www.msi.com/Motherboard/X370-GAMING-PLUS/Specification) feature two full-sized x16 PCIe connections, but the motherboard specs say that they function as either x16 (if using one GPU) or x8/x8 (if using two GPUs). Does not being able to run them at x16/x16 matter for hash rates? If not then could I potentially use another Gen2 slot for another GPU (even though it's an x4)?

Let me know if this makes any sense.

It's not going to matter.  That board has six pcie slots and you could use all six of them for mining, if you wanted to.  It makes no difference as far as your hash rates if the gpu is in a x16 slot or not.  The boards I use only have (2) x16 slots and I use all six slots on the board for mining gpu's.

[json111]

Ok thanks, that puts my mind at ease. But why does it not matter? Isn't GPU mining a really computationally intensive process? Is it just that Gen3 lines are advanced enough that they can handle any throughput that GPU/CPU pathway requires?

[malthrax]

Ok thanks, that puts my mind at ease. But why does it not matter? Isn't GPU mining a really computationally intensive process? Is it just that Gen3 lines are advanced enough that they can handle any throughput that GPU/CPU pathway requires?

The primary reason for having 16 PCIe lanes from your graphics card direct into the CPU is for loading huge texture maps for 3D modeling/rendering (either in video games, or CGI generation).  For crypto mining, there's simply not enough data being pushed back & forth from the CPU to the GPU to require all 16 ( or even 8 ) lanes.

[QuintLeo]

Cryptocoin mining is low bandwidth, so the use of even 1x slots works fine with little or ZERO impact on hashrates.

 There are other stuff you can do with a PC that IS bandwidth-intensive though, like Gaming or running the Folding@home client, where anything less than a 8x PCI-E 3.0 or 16x PCI-E 2.0 slot can have a measurable impact.