Break-even index / RTX 5090 / DeepSeek V4 Flash / Ohio
Will a RTX 5090 build beat DeepSeek V4 Flash in Ohio?
On cost alone, this never pays off — the cloud bill ($3.15/mo) is at or below your electricity bill ($10.87/mo). Buy it for sovereignty, not savings.
How to read it: OWN — the rig pays for itself inside 18 months. HYBRID — break-even lands between 18 and 36 months; real, but slow. RENT — it never pays off before the hardware is due for replacement. Every formula and threshold is public on the methodology page.
The numbers
| Build cost (RTX 5090 build) | $3,500 ($3,000–$4,000) |
|---|---|
| Hardware amortized (3 yr) | $97.22/mo |
| Electricity in Ohio ($0.161/kWh) | $10.87/mo (67.5 kWh) |
| Local total cost of ownership | $108/mo |
| DeepSeek V4 Flash at the same usage | $3.15/mo |
| Break-even | never — the cloud bill is below the electricity bill |
Assumes the "coding assistant" preset: ~15M tokens/month, 3 h/day active, 5 h/day idle. DeepSeek V4 Flash priced at $0.14/M in, $0.28/M out (verified 2026-07-05). Rig ceiling: 70B+ with real context windows. Jargon: VRAM is the GPU memory that decides which models fit; Q4 is 4-bit quantization — a smaller, faster copy of a model with a slight quality cost.
See your verdict — then tweak every number →