Threadripper TRX motherboards, RAM, and PCIe lanes

Quartz · 5 Feb 2020 at 12:37

Are there any TRX40 motherboards that can run 3 or 4 slots at a full x16? The upcoming 3990 is expected to have 88 PCIe lanes so it seems a shame to cripple it.

Similarly, RAM seems to be limited to 256 GB when the competitor product, the Apple Mac, can have over 1 TB. Is that actually correct? And 256 GB RAM seems a trifle low for a 64 core CPU anyway.

Are we going to see a slew of BIOS upgrades, motherboard revisions, or both? Wasn't there at one point going to be a TRX80 motherboard?

Or is this simply product - Threadripper vs Epyc - differentiation?

Quartz · 6 Feb 2020 at 16:31

Blackbadger said:
I believe all vendors offer a board with 4x16 slots (some of the "budget" ones do not, some do").

Unfortunately the boards seem to be physically four 16x but electrically two 16x and two 8x.

Quartz · 6 Feb 2020 at 16:39

Vince said:
The x399 Taichi has 4x pcie x16 so surely one of the new boards must be comparable?

Good find! I'd missed that one. But only 3 slots:

3 x PCI Express 4.0 x16 Slots (PCIE1/PCIE3/PCIE4: single at x16 (PCIE1); dual at x16 (PCIE1) / x16 (PCIE3); triple at x16 (PCIE1) / x16 (PCIE3) / x16 (PCIE4)

Quartz · 6 Feb 2020 at 17:02

Vince said:
It has 4 slots.

I was referring to and quoting from, the Taichi TRX40.

The only reason i know this is that i own quite a few x399 boards The trx40 has 3 which seems odd. Why have fewer than the last gen?

I'm guessing the TRX40 has three x16 slots so that all are x16 rather than two x16 and two x8.

Quartz · 7 Feb 2020 at 00:16

amigafan2003 said:
Apple Mac Pro uses a workstation class motherboard/cpu - the direct competitor to that is EPYC (both on spec and price), not HEDT Threadripper

I was under the impression that Epyc was for servers and Threadripper for workstations, with the Ryzen 39xx for HEDT.