Qwen3 235B-A22B on Mac Studio M5 Ultra 512 GB
235.094B (22B active) on 512 GB at 1,200 GB/s. Hardware details · Model details
Memory budget at 8K context
How the estimate is calculated
- Decode: reading 22.0B active parameters at 8.50 bits/weight takes 22.23 ms at 1200 GB/s x 88% achieved efficiency.
- MoE routing penalty of 15% applied: expert gathers are less bandwidth-efficient than a dense sweep.
- Prefill: 240 TFLOPS (FP16) x 1.69 calibrated against measured prefill on this platform x 22% assumed model-FLOPs utilisation, divided by 2 x 71.9B parameters per token.
- Prefill uses 71.9B effective parameters, not the 22B active in decode: a batch of hundreds of tokens routes across most of the expert pool.
- MoE decode depends on how well the engine batches expert gathers; real results vary more than for dense models.
- Prefill throughput is highly engine-dependent. Flash attention, batch size and quantized KV all move this number substantially, and for sparse mixture-of-experts models it is the least reliable figure we produce.
- This is a calculated estimate, not a measurement. It assumes a single request, a short prompt, no speculative decoding and a warm model already resident in memory.
Estimator version estimator_v1. Stored with every estimated row so old estimates can be regenerated when the model improves.
| Quantization | Weights | Total needed | Utilisation | Fit | Max context |
|---|---|---|---|---|---|
MLX 4-bit | 128.1 GB | 134.4 GB | 31% | Comfortable | 256K |
Q4_K_M | 136.7 GB | 143.3 GB | 33% | Comfortable | 256K |
Q8_0recommended | 237.3 GB | 246.9 GB | 57% | Comfortable | 256K |
BF16 | 437.9 GB | 453.5 GB | 104% | Does not fit | 0 |
The $100 comparison uses the Codex Pro 5x / Claude Max 5x plans. A fixed planning conversion is used for USD. This compares monthly spend only: subscriptions have usage limits, local hardware has different capabilities and constraints, and taxes or regional pricing may change the charged amount. Prices checked 7 September 2026.
Monthly breakdown
| Depreciation 7,945 over 5 years, straight-line to a 3,405 residual | $132.41 |
| Electricity 9.9 kWh/month at 0.140/kWh | $1.38 |
| Cost of capital 4.0%/yr on 7,377 average capital employed | $24.59 |
| Monthly cost before tax | $158.39 |
| Electricity tax shield Running costs are deductible business expenses | −$0.29 |
| First-year expensing §179 (100.0%) | −$39.72 |
| Monthly economic cost after tax | $118.37 |
Three different numbers, deliberately
Assumptions and sources (verified 2026-09-07)
- VAT rate: No US federal VAT · verified 2026-09-07
- Marginal tax rate: IRS Publication 542 — Corporations · verified 2026-09-07
- VAT recoverable fraction: site assumption · verified 2026-09-07
- Useful life: IRS Publication 946 — How To Depreciate Property · verified 2026-09-07
- Electricity price: Site assumption · verified 2026-09-07
| Hosted model | USD/1M output | Break-even | API at your volume | Verdict | Comparison type |
|---|---|---|---|---|---|
| Qwen3.8 Flash Alibaba Cloud | $0.42 | 76.9M/mo | $7 | API cheaper | Different model |
| DeepSeek-V4 Flash DeepSeek | $0.66 | 48.9M/mo | $11 | API cheaper | Different model |
| DeepSeek-V4 Pro DeepSeek | $1.98 | 16.3M/mo | $34 | API cheaper | Different model |
| DeepSeek V4 Pro (Together) Together AI | $4.40 | 5.6M/mo | $99 | API cheaper | Different model |
| GLM-5.3 Z.ai | $4.40 | 7.6M/mo | $73 | API cheaper | Different model |
| Claude Haiku 4.5 Anthropic | $5.00 | 9.1M/mo | $61 | API cheaper | Different model |
| Hardware | Decode | Price | Fit |
|---|---|---|---|
| Mac Studio M5 Ultra 256 GB | ~51.5–74.1 t/s | €9.599 | Comfortable |
| Mac Studio M3 Ultra 256 GB | ~29.2–42.1 t/s | €6.299 | Comfortable |
| Mac Studio M3 Ultra 512 GB | ~16.9–24.4 t/s | €9.199 | Comfortable |
| CPU-only workstation (Ryzen 9950X, 192 GB DDR5) | ~2.5–3.6 t/s | €1.699 | Comfortable |
Compare Mac Studio M5 Ultra 512 GB against Mac Studio M5 Ultra 256 GB →
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