Threadripper TRX motherboards, RAM, and PCIe lanes

Quartz

Quartz

Quartz

Soldato
Joined
1 Apr 2014
Posts
19,180
Location
Aberdeen
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?
 
I believe all vendors offer a board with 4x16 slots (some of the "budget" ones do not, some do").
Ram capacity is limited currently by the tested amount qualified by the board producers. As 32gb dimms are the max capacity available for regular dimms, that is the current quoted maximum. 8x32=256
It is possible a board vendor could offer more ram slots and therefore greater capacity.
On the previous thread ripper platform, 128gb was the max capacity, however when 32gb dimms became available, people were able to drop them in and it worked fine.
Ryzen Threadripper CPUs can support up to 2TB of RAM, but good luck getting modules that large to hit 2TB.

The Macpro uses a XEON server class CPU - Akin to Epyc. As standard these use server class ram RDIMM's which provide greater capacity to standard ram, at the cost of speed and money. Their motherboard also has more ram slots. As of today a 128gb RDIMM is around £1800 Making Apples - Request of an additional £22500 for 1.5tb "fair" :eek:
In contrast 128gb in 4x regular Dimms is around £600 which are also a lot faster.

All platforms support ecc, however this maybe motherboard dependent. I have read some vendors claim to have rdimms working on their x399/trx40 platforms unofficially. - don't expect any support or 100% compatibility.
Amd announced trx80 was a rumor by 3rd parties and have no plans for it.

I expect we will see 64gb "regular" dimms at some point. however for the time being, as with most things you can do amazing things with consumer parts however when you need more, the cost of going to business grade components can be costly.
 
Quartz said:
I was referring to and quoting from, the Taichi TRX40.



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

Yea i worked that out after i posted, my bad! Im surprised there isnt a board out there that "has it all" so to speak.
 
Quartz said:
Unfortunately the boards seem to be physically four 16x but electrically two 16x and two 8x.
Click to expand...

Yes, but they are all gen 4, so two at 16x and two at 8x is still more bandwidth than four at 16x for gen 3.

A gen 4 8x slot is the same bandwidth as a gen 3 16x slot.

Quartz said:
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.
Click to expand...

They aren't really crippling the boards esp when you consider most TRX40 boards have three m.2 slots.

Just checked my Strix specs - it has 3 x 16x, 1 x 4x and 3x m.2 slots - so that's 64 lanes straight away even before you get to the two network ports, wifi and USB ports (which go via the chipset).

Vince said:
. Why have fewer than the last gen?
Click to expand...

Because barely anyone in the HEDT space uses sli/xfire or all the full size PCIe slots. Those that do have a use case for that, there's Epyc.
 
Last edited by a moderator:
Quartz said:
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.
Click to expand...

Apple Mac Pro uses a workstation class motherboard/cpu - the direct competitor to that is EPYC (both on spec and price), not HEDT Threadripper
 
Last edited by a moderator:
Quartz said:
I was under the impression that Epyc was for servers and Threadripper for workstations, with the Ryzen 39xx for HEDT.
Click to expand...
3960x, 3970x and 3990x (sTRX4 socket) are Threadripper/HEDT. 3900x and 3950x (am4 sockey) are mainstream desktop.

Plain Ryzen - mainstream desktop
Ryzen Threadripper - HEDT
EPYC - workstation and server.
 
You must log in or register to reply here.
Back
Top Bottom