Mixtral 8x22B on RTX 3090 workstation (Ryzen 9 7950X, 64 GB)
140.63B (39B active) on 24 GB at 936 GB/s. Hardware details · Model details
No calculated fit. Mixtral 8x22B does not fit under standard overhead assumptions at
Q4_K_M: the model calculates 87.0 GB required against 22.1 GB usable.CompatibilityDoes not fit
Calculated fit
No
Calculated Requires more than 97% of usable memory. Needs a smaller quantization or more memory.
Smallest catalogued quantization
Q4_K_M
Calculated gguf
Memory required
87.0 GB
Calculated of 22.1 GB usable — 394%
Max practical context
0
Calculated model supports 64K
Memory budget at 8K context
Model weights ⓘ
81.8 GB Calculated
KV cache ⓘ
1.8 GB Calculated
Runtime overhead ⓘ
3.5 GB Estimated
Total required
87.0 GB Calculated
Headroom ⓘ
-64.9 GB Calculated
No quantization in our catalogue fits this machine.
Discrete GPU: 24 GB of VRAM, of which we assume 92% is usable after driver and context overhead.
Mixture of experts: all 140.63B parameters must be resident in memory even though only ~39B are active per token. Memory follows total parameters; speed follows active parameters.
Performance
Estimated performance · recommended Q4_K_M
Decode, prefill and TTFT below are estimates for Q4_K_M. We do not have a comparable Q4_K_M measurement on this machine.
Estimated decode
—
Estimated Q4_K_M; calculated range
Estimated prefill
—
Estimated Q4_K_M; calculated range
Estimated TTFT at 8K
~19.8–41.3 s
Estimated Q4_K_M; calculated range
Hardware load reference
600 W
Official spec hardware TDP; not this model run
No throughput figures for this configuration. We do not estimate performance for a model that cannot load.
How the estimate is calculated
- Decode: reading 39.0B active parameters at 4.85 bits/weight takes 33.68 ms at 936 GB/s x 75% achieved efficiency.
- MoE routing penalty of 15% applied: expert gathers are less bandwidth-efficient than a dense sweep.
- Prefill: 142 TFLOPS (FP16) x 32% assumed model-FLOPs utilisation, divided by 2 x 74.1B parameters per token.
- Prefill uses 74.1B effective parameters, not the 39B 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.
Submit a benchmarkSubmissions stay pending until reviewed.
This model at other quantizations on this machine
| Quantization | Resident | Disk | Total needed | Utilisation | Fit | Max context |
|---|---|---|---|---|---|---|
Q4_K_Msmallest listed | 81.8 GB | 81.8 GB | 87.0 GB | 394% | Does not fit | 0 |
Q5_K_M | 95.9 GB | 95.9 GB | 101.6 GB | 460% | Does not fit | 0 |
Q8_0 | 141.9 GB | 141.9 GB | 148.9 GB | 675% | Does not fit | 0 |
BF16 | 261.9 GB | 261.9 GB | 272.6 GB | 1234% | Does not fit | 0 |
Cost of running Mixtral 8x22B on this machineUnited States (federal) · C corporation · 8h/day
Monthly economic cost
$26
Calculated after tax
Codex/Claude Code
$100/mo
≈ $100/mo · local is $74 less
Net cash at purchase
$1,981
Calculated VAT not reclaimable
Total over 5 years
$1,578
Calculated after tax, after resale
Cost per USD/1M tokens
—
Calculated
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.
Purchase-price input: $1,981 in United States (federal), tax/VAT excluded · estimated · Used market exact-match reference (converted catalogue estimate). This is the localized purchase input; the after-tax economic cost is calculated separately below.
Monthly breakdown
| Depreciation 1,545 over 5 years, straight-line to a 436 residual | $25.75 |
| Electricity 31.3 kWh/month at 0.140/kWh | $4.38 |
| Cost of capital 4.0%/yr on 1,208 average capital employed | $4.03 |
| Monthly cost before tax | $34.16 |
| Electricity tax shield Running costs are deductible business expenses | −$0.92 |
| First-year expensing §179 (100.0%) | −$6.93 |
| Monthly economic cost after tax | $26.30 |
Three different numbers, deliberately
Cash cost
$1,981
Money that leaves the bank account on day one, net of reclaimable VAT.
Accounting depreciation
$25.75/month
$1,545 written down over 5 years to a $436 residual.
After-tax economic cost
$26.30/month
Depreciation plus running costs plus cost of capital, less the tax those deductions save. This is the figure to compare between machines.
Assumptions and sources (verified 2026-09-07)
VAT rate
0% Official spec
VAT recoverable
0% Official spec
Federal C-corporation estimate at the flat 21% rate. Pass-through entities should use the sole-proprietor estimate as a rougher proxy.
Effective deduction rate
21.00% Calculated
Headline marginal rate 21.00%.
Depreciation
5 years, straight-line Assumption
Residual value
$436 (22%) Assumption
Extrapolated.
Electricity
$0.140/kWh Assumption
Average power draw
178 W Calculated
Load 600 W for 20% of powered hours, idle 72 W for the rest — a machine that is on is not generating tokens the whole time.
Investment allowances
§179 100.0% Official spec
Worth $416 in total — first-year expensing that replaces later tax depreciation.
Cost of capital
$4.03/month Assumption
- 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
Federal planning estimate only, not tax advice. State and local income tax, sales/use tax and incentives are excluded. It assumes 100% business use, a Section 179 election, enough business income to use it, and that the full annual limit remains available.
Mixtral 8x22B on other hardware
| Hardware | Decode | Price | Fit |
|---|
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Compare RTX 3090 workstation (Ryzen 9 7950X, 64 GB) against Used RTX 4090 workstation (24 GB) →
Compare RTX 3090 workstation (Ryzen 9 7950X, 64 GB) against Used RTX 4090 workstation (24 GB) →