Yi 1.5 34B on Dual used RTX 4090 workstation (48 GB)
34.389B on 48 GB at 2,016 GB/s. Hardware details · Model details
Yes. Yi 1.5 34B fits on Dual used RTX 4090 workstation (48 GB) at the recommended
Q5_K_M configuration, requiring approximately 26.5 GB at 4K context. Practical context capacity is 4K.CompatibilityComfortable
Calculated fit
Yes
Calculated Uses under 80% of usable memory. Room for a long context and other work.
Recommended quantization
Q5_K_M
Calculated gguf
Memory required
26.5 GB
Calculated of 42.2 GB usable — 63%
Max practical context
4K
Calculated model supports 4K
Memory budget at 4K context
Model weights ⓘ
23.5 GB Calculated
KV cache ⓘ
0.9 GB Calculated
Runtime overhead ⓘ
2.1 GB Estimated
Total required
26.5 GB Calculated
Headroom ⓘ
15.7 GB Calculated
Highest-precision quantization that leaves headroom: uses 63% of usable memory at 8K context.
2 GPUs providing 48 GB aggregate VRAM. Assumes tensor- or layer-parallel sharding; each GPU carries its own context and communication buffers.
Multi-GPU throughput depends heavily on interconnect. Without NVLink or NVSwitch, tensor parallelism over PCIe adds latency that partially offsets the extra bandwidth.
Performance
Estimated performance · recommended Q5_K_M
Decode, prefill and TTFT below are estimates for Q5_K_M. We do not have a comparable Q5_K_M measurement on this machine.
Estimated decode
—
Estimated Q5_K_M; calculated range
Estimated prefill
—
Estimated Q5_K_M; calculated range
Estimated TTFT at 8K
~2.5–5.2 s
Estimated Q5_K_M; calculated range
Hardware load reference
980 W
Measured machine-level load; 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
- Multi-GPU: 1008 GB/s per card, with each additional card contributing 40% of its bandwidth — 1411 GB/s effective, not the 2016 GB/s aggregate. Cross-GPU collectives use PCIe rather than a dedicated GPU fabric.
- Decode: reading 34.4B active parameters at 5.69 bits/weight takes 22.22 ms at 1411 GB/s x 78% achieved efficiency.
- Prefill: 330 TFLOPS (FP16) x 2 for native FP8 tensor cores x 26% assumed model-FLOPs utilisation, divided by 2 x 34.4B parameters per token.
- 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_M | 20.0 GB | 20.0 GB | 22.9 GB | 54% | Comfortable | 4K |
Q5_K_Mrecommended | 23.5 GB | 23.5 GB | 26.5 GB | 63% | Comfortable | 4K |
Q8_0 | 34.7 GB | 34.7 GB | 38.1 GB | 90% | Borderline | 4K |
BF16 | 64.1 GB | 64.1 GB | 68.3 GB | 162% | Does not fit | 0 |
Cost of running Yi 1.5 34B on this machineUnited States (federal) · C corporation · 8h/day
Monthly economic cost
$48
Calculated after tax
Codex/Claude Code
$100/mo
≈ $100/mo · local is $52 less
Net cash at purchase
$3,692
Calculated VAT not reclaimable
Total over 5 years
$2,873
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: $3,692 in United States (federal), tax/VAT excluded · estimated · Used market (Marktplaats/eBay) (converted catalogue estimate). This is the localized purchase input; the after-tax economic cost is calculated separately below.
Monthly breakdown
| Depreciation 2,880 over 5 years, straight-line to a 812 residual | $48.00 |
| Electricity 47.9 kWh/month at 0.140/kWh | $6.70 |
| Cost of capital 4.0%/yr on 2,252 average capital employed | $7.51 |
| Monthly cost before tax | $62.21 |
| Electricity tax shield Running costs are deductible business expenses | −$1.41 |
| First-year expensing §179 (100.0%) | −$12.92 |
| Monthly economic cost after tax | $47.88 |
Three different numbers, deliberately
Cash cost
$3,692
Money that leaves the bank account on day one, net of reclaimable VAT.
Accounting depreciation
$48.00/month
$2,880 written down over 5 years to a $812 residual.
After-tax economic cost
$47.88/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
$812 (22%) Assumption
Extrapolated.
Electricity
$0.140/kWh Assumption
Average power draw
272 W Calculated
Load 980 W for 20% of powered hours, idle 95 W for the rest — a machine that is on is not generating tokens the whole time.
Investment allowances
§179 100.0% Official spec
Worth $775 in total — first-year expensing that replaces later tax depreciation.
Cost of capital
$7.51/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.
Yi 1.5 34B on other hardware
| Hardware | Decode | Price | Fit |
|---|
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