The verdict

CPU
Beelink SER5 MAX has 1.1x the CPU throughput (20,474 vs 18,053 PassMark).
Idle power
Beelink SER5 MAX idles lower (10W vs 12W) - cheaper to run 24/7.

Which wins for each job

Job Beelink SER5 MAX Lenovo M75q
Plex / Jellyfin ~3 streams ~3 streams
Frigate NVR add a detector add a detector
Proxmox / VMs 20,474 PassMark win 18,053 PassMark
Firewall / router 1 NICs 1 NICs
Local AI / LLM no slot no slot

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 Beelink SER5 MAX Lenovo M75q
Price (list) $279 $280
CPU AMD Ryzen 7 5800H AMD Ryzen 5 PRO 5650GE
Cores / threads 8 6
PassMark 20,474 18,053
iGPU Radeon Vega 8 Radeon Vega 7
NICs 1 1
NIC model Realtek 1GbE Realtek 1GbE
RAM max (GB) 64 64
M.2 free 0 0
PCIe slot none none
Idle (W) 10 12
TDP (W) 54 35