Forbidden Router/Homeserver Platform Recommendation

I built an AM5 Forbidden Router which is RAM and PCIE-limited. I’m seeking any thoughts the options below given my use case. This machine my first foray into homelab and although I’m proud that I’ve had over a year of uptime without major incident, I have made decisions that I regret due to ignorance. You don’t know what you don’t know what you don’t know and so on.

Quick Version
Should I add RAM to my AM5 my home server, or move to Threadripper for additional PCIE lanes and RAM? 5xxx costs about $1800, 7xxx costs about $2300. I will soon occupy all three PCIE slots on my X670E board with a x16 device running at x8.

Current System Description:

  • CPU: 7900x (24 threads)
  • RAM: 64 GB DDR5 (2x32 ECC UDIMM)
  • PCIE layout: 5x16 (8); 5x16 (8); 4x16 (4)
  • PCIE Devices: LSI SAS HBA (3x8 - TrueNAS), Intel X710-DA4 (3x8 -pfSense), vacant
  • planning to add 4090 for AI services running on always on Windows Desktop

VMs (w/ services):

  • pfSense;
  • TrueNAS;
  • Debian 12 (docker - portainer, nextcloud, jellyfin, immich, traefik, netbird, authentik etc…)

Windows Desktop
I run ai services (ollama, whipser, stable diffusion) on a Windows gaming PC with a 4090.

Goals

  • I want to move my 4090 from my Windows desktop to a Linux VM. The Linux VM would take over ai services and also have access to 4090 for tasks that would benefit from GPU acceleration.
  • I want a Linux VM with a desktop environment (4th VM) for web browsing and media playback. I don’t need, but would like to have a Windows VM with the same functionality.

Options
Option 1:

  • Add 64 GB DDR5 (2x32) for a total of 128 GB.
  • Replace X710-DA4 with X550-T2 (4x4). 4090 runs at 4x8.
  • RAM upgrade is not feasible in the future.
  • Cannot add more PCIE devices.

Cost: $350

Option 2:

  • Same as 1, but replace 64 GB (2x32) with 96 GB (2x48).
  • RAM up to 192 GB is feasible.

Cost: $600

Option 3:

  • Purchase a cpu/mobo combo: 5965wx (24 threads), wrx motherboard, 512 GB DDR4 (8x64 ECC RDIMM).
  • Can add more PCIE devices.
  • Can’t imagine needing more RAM.

Cost: $1800

Option 4:

  • Purchase a 7960x, trx50 motherboard and 128 GB DDR5 (2x64).
  • Can add more PCIE devices.
  • RAM up to 256 GB is ppossible.

Cost: $2300

I started with Server AM5 7950X replaced regular DDR5 with ECC DDR5 UDIMM and then later also bought a Siena Epyc 8004 with 24 cores.
An AM5 with ECC is great value and fit most needs, with a good motherboard that has ECC support and many M2 NVME slots. I use the ASUS B650E-E. I have moved a lot of services from VMs to CTs, which really lowers the need for lots of RAM. For example I avoid Truenas and use ZFS directly on Proxmox.
The Siena has 192 GB of RDIMM but I am never above 100+ GB used. I use a lot of the Siena PCIE slots for added NVME and Mellanox and Quad 2.5 GbE. Fun but not close to good value versus one or two AM5s well planned out.
Many RDIMMs and many PCI-E uses lots of more Watts than an efficient AM5. My Siena can do 59 watts from wall with one single RDIMM and no fast drives (only Gen 3.0 NVME. Once you install 6xRDIMMs, and fast Gen3+4+5 NVMEs and some high speed 10 Gbps and 25 Gbps NICs it’s constantly above 120 watts.

So in short, for Server/Router, option 1.

A 4090 on a server motherboard/Thread-ripper, would block many expensive PCI-E slots, unless you plan for a Riser Cable mounting.

1 Like

How much does electricity weigh in on your decision, as like the last guy said, TR uses a lot compared to AM5 - I’d rather have multiple AM5 systems if needed (scale out, not up).