The verdict

CPU
Minisforum MS-S1 Max has 1.5x the CPU throughput (54,895 vs 37,699 PassMark).
Idle power
GEEKOM A9 Max idles lower (7W vs 11W) - cheaper to run 24/7.
Local AI
Minisforum MS-S1 Max has a PCIe slot for a low-profile GPU - the other needs a DIY build for local LLMs.

Which wins for each job

Job GEEKOM A9 Max Minisforum MS-S1 Max
Plex / Jellyfin ~5 streams ~5 streams
Frigate NVR add a detector add a detector
Proxmox / VMs 37,699 PassMark 54,895 PassMark win
Firewall / router 2 NICs 2 NICs
Local AI / LLM no slot PCIe GPU slot win

Approximate - capacity estimates from curated specs, the same logic as the recommender. Verify against your exact setup. Prices move; check the retailer.

Full specs

Spec GEEKOM A9 Max Minisforum MS-S1 Max
Price (list) $999 $1,999
CPU AMD Ryzen AI 9 HX 370 AMD Ryzen AI Max+ 395
Cores / threads 12 16
PassMark 37,699 54,895
iGPU Radeon 890M (RDNA3.5) Radeon 8060S (RDNA3.5)
NICs 2 2
NIC model Realtek 2.5GbE dual Dual 10GbE
RAM max (GB) 128 128
M.2 free 1 1
PCIe slot none x16
Idle (W) 7 11
TDP (W) 54 130