Question Ryzen 9 3900x with dual GPU

Feb 13, 2020

I am building deep learning machine for my home. I am planning to use AMD ryzen 9 3900x with Nvidia Rtx 2080 to or other low end in RTX series which has NvLink support. Also I would use 1tb SSD with NVM e with 4.0 for fast transfer. 4 tb HDD for higher data.

I currently am planning to have just one GPU but would like to expand and add additional GPU after some time.

I know ryzen 9 has 24 PCIe lanes. 4 will be used for chipset.

My query is will the ryzen 9 3900x be able to handle 2 GPU/ dual GPU configuration.

Lane bandwidth can be sacrificed, I am more concerned with compatibility with the CPU and motherboard

If it (3900x) can't support 2 GPU s, should I go for Threadripper 3960x which is quite expensive at this time.

How much of Lane bandwidth is required for all of them combined.
Hey there,

The short answer is yes! :)

You're right, it does have only 24 PCIe lanes, but these are gen4. They are almost double the bandwidth of the PCIe gen3. So as long as the mobo you choose is rated for dual GPU (SLI/Xfire), then the x8/x8 option for dual GPU's is equivalent (well , almost) to 16x PCIe gen3. So bandwidth will not be an issue,

edit: I missed the 2nd and 3rd questions :)

Threadripper? No need. See above!

With 4 lanes for chipset/CPU, 16 lanes for GPU's, that leaves four for your peripherals.
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Just on the dual GPU thing. In gaming terms, you're talking about SLI/XFire, which means matching GPU's of the same model. You can also use two GPU's in a system too, but unless it's for specific usage like maybe running more monitors or something like that.
DX12 has support for multi-GPU that not only works across series but across brands. The question is if devs will take up the support. DX11 has previously out performed DX12 in the past, DX12 is now starting to take over benchmark figures. Maybe DX12 multi gpu will take off also . But for now, there isn't much point in having a dual GPU set up, apart from the gaming aspect, which means matching GPU's. That's pretty expensive.