General Discussions

[lancer]

I am selecting parts to build a home workstation using the Ryzen 9 7950X 16-core processor (socket AM5), but all of the X670E or B650E chipset motherboards I’ve seen only have a meager 3 or 4 PCIe slots, even on EATX boards, and none have both x16 and x8 slots. Any AM5 motherboard recommendations?

Minimum PCIe slots and M.2 connectors required:
One x16 - Graphics Card - PCIe 4.0 x16
One x8 – RAID Controller Card – PCIe 4.0 x8
One x1 – HDD controller adapter card (to access old IDE drives).  Alternate slot use for sound card.
One xAny – Blank non-electrical card on which the RAID controller battery backup is secured.
Two - M.2-2280 connectors for PCIe 4.0 x4 NVMe SSD

I read that another AM5 chipset is apparently coming, the X690E, and that may be more workstation friendly than X670E/B650E. The image I saw showed an ASUS X690E motherboard having seven PCIe slots and eight memory slots. But who knows when those will be available.  Until then, what AM5 motherboard will work now, if any?

[FunkZ · Accepted solution]

You realize your minimum requirements call for 32+ PCIe lanes and the 7950X only has 24 usable lanes? Yes the chipset can offer additional slave lanes but asking for 8+ more?

I know it's a big price jump but you may need to consider TRX50 and Threadripper 7960X, you'll have all the PCIe lanes you need.

[lancer]

According to chipset specs, the X670E chipset has up to 44 usable PCIe lanes (24 direct processor PCIe 5.0), and the B650E has up to 36 usable (24 direct processor PCIe 5.0).  For the X670E, the 24 direct processor lane allocation is 16 to the graphics slot (x16 or two x8), 4 to NVME SSD, and 4 general purpose.  Beside those 24 direct processor lanes, there are 12 PCIe 4.0 lanes and 8 PCIe 3.0 lanes.  The B650E has the same 24 direct processor lanes, but only 12 additional PCIe 4.0 and 3.0 lanes.  So, unless I'm misunderstanding something, my build is within spec.  I'm just finding that motherboard manufacturers have used those 44 (X670E) and 36 (B650E) lanes differently than I need, more gamer-oriented than workstation for the motherboards I've seen so far.

[lancer]

Interesting that while looking into the Threadripper 7960X, I found rare-to-find benchmarks for financial services and probability applications, which is my use case. (benchmarks by GamersNexus) The benchmark scores were: Threadripper 7960X @ 12.06, Ryzen 9 7950X @ 8.68, and Intel i9-14900K @ 6.77. So the eight additional cores of the Threadripper 7960X provide a 39% improvement over the Ryzen 9 7950X in that multi-thread test.

With no applicable AM5 motherboards for the Ryzen 9 7950X, it looks like the choice is a Threadripper 7960X.  Definitely no capability issues with socket TR5 motherboards.