Hi All,

I am considering switching out a few parts on my main server/NAS (Running Unraid) but there are a few things I am unsure about.

Specs:

  • CPU: Ryzen 3700x
  • Motherboard: ASUS ROG Strix B450-F
  • RAM: 32 GB DDR4 2400MHz
  • GPU: Quadro P2000
  • HBA: LSI SAS2308-8i (9217), HP 487738-001 (24i 4e)
  • Storage: 2x 2TB Gen4 NVMe, 24xMixed HDDs (110 TB)

As you can see I am deficient a few PCIe lanes. Looking at the alternatives it seems that there are a few good deals on some EPYC CPUs.

On the motherboard, there are 10 Slimline 4i connectors, 2 wired for 8 SATA devices. I have no experience with this connector so I am not sure but I was thinking if it would be possible to use 6 of the ports to connect all 24 drives with a Slimline to SFF8087 connector freeing up the PCIe slots for future use. Also if anyone knows the correct connector name for Slimline ports that would be great as I am looking for cables and I don’t think I am finding the correct ones.

Secondly, the 2 m.2 connectors on the motherboard are both wired for Gen3 NVMe SSDs so I would be losing some performance from the Gen4 Drives. I do have 4xGen3 2TB NVMe SSDs lying around so I am wondering if it would be better to move the Gen4 Drives to my gaming PC and use a 16x PCIe card for the 4xGen3 drives.

The issue would be that it doesn’t seem sensible to use 4 SSDs for a cache. The other idea I had would be to pick up some Gen4 U.2 Drives to replace the cache but I am not sure what is the best way to connect those drives.

If anyone has any experience with EPYC or has some recommendations I would love to hear it. I don’t have any specific budget but as with any homelab I am looking to use parts I already have and try to do it as cheaply as possible.

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  • aetherspoon@alien.topBEnglish
    1·
    1 year ago

    Are you actually in PCIe lane contention?

    You have a dGPU using an x16 slot, an HBA using an x8 slot, and a SAS expander using an… x4 slot, I think? That last one I’m not sure about, please correct me if/when I’m wrong. While yes, that adds up to needing 28 lanes of PCIe on paper… most dGPUs don’t actually need an x16 slot. In fact, it wouldn’t surprise me if you could get away with an x4 slot - meaning you really just need an x8, x4, and x4 - which adds up to sixteen lanes.

    Now, I don’t know what you’re using that dGPU for, it is entirely possible you have some type of need for that many lanes… but you might be able to just shuffle them around and make things work better than they are now.

    Far be it for me to stop a homelabber from throwing more money at the hobby of course, but maybe you don’t have to?