Rig Finder index / 8B / Always-on agent server / Tennessee
Best rig to run an 8B model for always-on agent server in Tennessee
For an 8B model at this workload, the Mini-PC pays off fastest — break-even ~1 months, keeping $22,853 over 3 years versus Claude Sonnet 4.6.
Same workload, same cloud, same electricity — we swap only the hardware and rank by real break-even. Rigs that can't run an 8B model are shown, never recommended. Compared against Claude Sonnet 4.6 ($3/M in, $15/M out); change the cloud in the lab.
Every build, ranked
| Rig | Build | 8B tok/s | Local/mo | Break-even | Verdict |
|---|---|---|---|---|---|
| Mini-PCbest payoff | $750 | 22estimated | $25.19 | ~1 mo | OWN |
| RTX 3090 (used) | $1,200 | 85estimated | $53.61 | ~2 mo | OWN |
| 2× RTX 3090 | $2,250 | 90estimated | $96.66 | ~4 mo | OWN |
| RTX 4090 | $2,300 | 120estimated | $86.39 | ~4 mo | OWN |
| Mac M-series | $3,000 | 65estimated | $87.39 | ~5 mo | OWN |
| RTX 5090 | $3,500 | 180estimated | $126 | ~6 mo | OWN |
Assumes always-on agent server use: ~120M tokens/month, 10h/day active, 14h/day idle, at Tennessee electricity ($0.130/kWh). Speeds are our estimates; community-measured tok/s live on the interactive Rig Finder and the benchmarks board. Every formula is on the methodology page.
Run this with your exact numbers →