Processors

[rockyee]

I'm looking at getting 6 graphics cards for rendering and it requires 8x pcie lanes per card. I saw this article here, which shows 64 lanes on Threadripper supporting 7 gpu's @ 8x speed:

https://www.techpowerup.com/236017/amd-ryzen-threadripper-memory-and-pcie-detailed-what-an-mcm-entai...

But I haven't seen any motherboards that actually utilize this design. My other option right now is to get an HEDT Intel system that will support 6 cards.

[black_zion]

fsadough‌ this fall under your area of expertise?

[fsadough]

Correct, no motherboard out there yet

[rockyee]

Thanks for taking a look. I get the feeling the answer is no. I don't see any x399 boards that have more than 4 pcie 16x slots

[misterj]

rockyee, the answer is certainly yes, but requires work you may not be willing to do.

I failed to say that you will need to go into BIOS and enable the Over 4GB setting to allow more memory space for the Memory Mapped I/O (MMI) for all those Video Cards.  Enjoy, John.

[misterj]

rockyee, TR does have 64 PCIe lanes, but 4 are dedicated to the CPU, so I assume you can use 60, via the PCIe sockets.  I know nothing about Intel, but it seems to me that 64 lanes is the maximum (standard) at the moment.  I guess Intel could have expanded their lane count since TR was announced, but when TR was announced, it had more lanes than anyone, meaning Intel.  My MB has 2 PCIe sockets of x16 and 2 of x8.  That should offer 48 lanes, just as you need.  My old ASRock MB has the same.  I do not know what you mean by

But I haven't seen any motherboards that actually utilize this design.

If you are saying having enough slots for 6 x8 slots cards, I am sure you are correct.  You will need to find x8 extender cables to reach to an external box supplying power to all those cards.  The Mining industry does this and uses many more than 6 cards but only two lanes each - lots and lots of compute, little data motion.  You will need to do some research.  Do you really need 8 lanes per card?  I ran across a mining MB that has 20 x2 slots PCIe slots.  Enjoy, John.

EDIT: My specifications:

MSI X399 Creation, Threadripper 2990WX, 3xSamsung SSD 970 EVO RAID0, 4xSSD 960 EVO on
MSI AeroXpander RAID10, 1TB & 500 GB WD Black, G.SKILL Flare X F4-3200C14Q-32GFX,
Windows 10 x64 Pro, EnerMax-MaxTytan-EDT1250EWT, Enermx Liqtech TR4 280 CPU Cooler,
Radeon RX580, Aquantia 10 GbpS Ethernet NIC, UEFI E7B92AMS.120, AGESA SummitPI-SP3r2-
1.1.0.2.