The verdict

CPU
Minisforum N5 Pro has 1.5x the CPU throughput (33,292 vs 22,934 PassMark).
Idle power
Dell OptiPlex 7020 Micro idles lower (9W vs 33W) - cheaper to run 24/7.
Networking
Minisforum N5 Pro has more NICs (2 vs 1) - better for a firewall or VLAN trunk.
RAM ceiling
Minisforum N5 Pro takes more RAM (96GB vs 64GB).
Local AI
Minisforum N5 Pro has a PCIe slot for a low-profile GPU - the other needs a DIY build for local LLMs.

Which wins for each job

Job Dell OptiPlex 7020 Micro Minisforum N5 Pro
Plex / Jellyfin ~5 streams ~5 streams
Frigate NVR ~4 cameras win add a detector
Proxmox / VMs 22,934 PassMark 33,292 PassMark win
Firewall / router 1 NICs 2 NICs win
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 Dell OptiPlex 7020 Micro Minisforum N5 Pro
Price (list) $750 $899
CPU Intel Core i5-14500T AMD Ryzen AI 9 HX PRO 370
Cores / threads 14 12
PassMark 22,934 33,292
iGPU UHD 770 Radeon 890M (RDNA3.5)
NICs 1 2
NIC model Intel 1GbE Marvell AQC113 10GbE plus Realtek 5GbE
RAM max (GB) 64 96
M.2 free 0 3
PCIe slot none x16
Idle (W) 9 33
TDP (W) 35 54