RTX 3090 workstation (Ryzen 9 7950X, 64 GB) vs Used RTX 4090 workstation (24 GB)
The RTX 4090 is about 12% faster across 7 like-for-like model configurations. Compare model compatibility, like-for-like tokens/sec and ownership cost below.
RTX 3090 workstation (Ryzen 9 7950X, 64 GB) · Used RTX 4090 workstation (24 GB)
Verdict
- throughputThe Used RTX 4090 workstation (24 GB) delivers approximately 12% higher aggregate decode throughput across 7 like-for-like model configurations (same quantization, runtime, context and inference settings).
- capacityBoth machines run all 8 compared models in their best practical configurations. Compare their quantizations and evidence labels before treating any throughput difference as a hardware result.
- costAt 8 hours a day, the RTX 3090 workstation (Ryzen 9 7950X, 64 GB) has approximately 2% lower total monthly cost ($26 against $27), for a C corporation in United States (federal).
- evidenceAll 7 like-for-like throughput rows are estimates. Treat the ranking as indicative and the margins as uncertain.
- recommendationThere is no single answer: the Used RTX 4090 workstation (24 GB) is faster, the RTX 3090 workstation (Ryzen 9 7950X, 64 GB) is cheaper to own, and the Used RTX 4090 workstation (24 GB) gives more throughput per unit of purchase currency. Pick on whichever constraint actually binds you — interactive latency, monthly budget, or capacity headroom for larger models later.
Hardware
| RTX 3090 workstation (Ryzen 9 7950X, 64 GB) | Used RTX 4090 workstation (24 GB) | |
|---|---|---|
| Purchase price estimate | $1,981 * | $2,071 * |
| Memory | 24 GB | 24 GB |
| Memory bandwidth | 936 GB/s | 1,008 GB/s |
| Usable bandwidth indicator | 702 GB/s (75%) | 806 GB/s (80%) |
| Nominal power | 600 W | 600 W |
| Measured load power | — | 520 W |
| Idle power | — | 60 W |
| Architecture | discrete gpu | discrete gpu |
Like-for-like performance7 comparable models
Ternary Bonsai 2 27BNemotron 3.5 Lightning 30B-A3BQwen3-Coder 30B-A3BQwen3 30B-A3BGemma 4 26B-A4Bgpt-oss-20bGranite 4.2 30BQwen3.8 27B
| Model | RTX 3090 workstation (Ryzen 9 7950X, 64 GB) | Used RTX 4090 workstation (24 GB) | Winner |
|---|---|---|---|
| Ternary Bonsai 2 27B 27.36B | — no matched configuration | — no matched configuration | Not comparable |
| Nemotron 3.5 Lightning 30B-A3B 31.578B (3B active) | ~213–307 t/s Q4_K_M | ~237–342 t/s Q4_K_M | Used RTX 4090 workstation (24 GB) +11% estimated · estimator_v1 · 8K context |
| Qwen3-Coder 30B-A3B 30.532B (3.3B active) | ~197–284 t/s Q4_K_M | ~221–317 t/s Q4_K_M | Used RTX 4090 workstation (24 GB) +12% estimated · estimator_v1 · 8K context |
| Qwen3 30B-A3B 30.532B (3.3B active) | ~197–284 t/s Q4_K_M | ~221–317 t/s Q4_K_M | Used RTX 4090 workstation (24 GB) +12% estimated · estimator_v1 · 8K context |
| Gemma 4 26B-A4B 25.806B (3.8B active) | ~154–221 t/s Q5_K_M | ~173–249 t/s Q5_K_M | Used RTX 4090 workstation (24 GB) +12% estimated · estimator_v1 · 8K context |
| gpt-oss-20b 20.915B (3.6B active) | ~205–295 t/s MXFP4 | ~228–329 t/s MXFP4 | Used RTX 4090 workstation (24 GB) +12% estimated · estimator_v1 · 8K context |
| Granite 4.2 30B 29.277B | ~31.4–45.2 t/s Q4_K_M | ~35.9–51.7 t/s Q4_K_M | Used RTX 4090 workstation (24 GB) +14% estimated · estimator_v1 · 8K context |
| Qwen3.8 27B 27.781B | ~33.1–47.6 t/s Q4_K_M | ~37.8–54.4 t/s Q4_K_M | Used RTX 4090 workstation (24 GB) +14% estimated · estimator_v1 · 8K context |
Hardware deltas are calculated only when quantization, runtime, exact context, execution/decode mode and relevant inference settings match. Measured and estimated results are never compared to each other. A difference under 10% is reported as a tie.
Best practical configuration
| Model | RTX 3090 workstation (Ryzen 9 7950X, 64 GB) | Used RTX 4090 workstation (24 GB) | Practical result |
|---|---|---|---|
| Ternary Bonsai 2 27B | — PTQ1_0 · estimated | 91.1 t/s PTQ1_0 · measured | Both fit; configurations may differ |
| Nemotron 3.5 Lightning 30B-A3B | ~213–307 t/s Q4_K_M · estimated | ~237–342 t/s Q4_K_M · estimated | Both fit; configurations may differ |
| Qwen3-Coder 30B-A3B | ~197–284 t/s Q4_K_M · estimated | ~221–317 t/s Q4_K_M · estimated | Both fit; configurations may differ |
| Qwen3 30B-A3B | ~197–284 t/s Q4_K_M · estimated | ~221–317 t/s Q4_K_M · estimated | Both fit; configurations may differ |
| Gemma 4 26B-A4B | ~176–253 t/s Q4_K_M · estimated | ~197–284 t/s Q4_K_M · estimated | Both fit; configurations may differ |
| gpt-oss-20b | ~205–295 t/s MXFP4 · estimated | ~228–329 t/s MXFP4 · estimated | Both fit; configurations may differ |
| Granite 4.2 30B | ~31.4–45.2 t/s Q4_K_M · estimated | ~35.9–51.7 t/s Q4_K_M · estimated | Both fit; configurations may differ |
| Qwen3.8 27B | ~33.1–47.6 t/s Q4_K_M · estimated | ~37.8–54.4 t/s Q4_K_M · estimated | Both fit; configurations may differ |
This is a deployment comparison: each machine uses its own recommended configuration. Different quantizations can change speed and quality, so these figures are not raw hardware benchmarks.
Economics — United States (federal), C corporation, 8h/day
| RTX 3090 workstation (Ryzen 9 7950X, 64 GB) | Used RTX 4090 workstation (24 GB) | |
|---|---|---|
| Purchase price estimate | $1,981 | $2,071 |
| Reclaimable VAT | $0 | $0 |
| Net cash at purchase | $1,981 | $2,071 |
| Monthly depreciation | $25.75 | $26.92 |
| Monthly electricity | $4.38 (31 kWh) | $3.75 (27 kWh) |
| Tax programme | §179 100.0% | §179 100.0% |
| Tax-programme benefit | $416 | $435 |
| Monthly economic cost | $26.30 | $26.84 |
| Total over 5 years | $1,578 | $1,611 |
Purchase prices are localized inputs in USD: tax/VAT excluded for RTX 3090 workstation (Ryzen 9 7950X, 64 GB) and tax/VAT excluded for Used RTX 4090 workstation (24 GB). Net cash and monthly economic cost then apply the selected United States (federal) / C corporation tax treatment. Tax assumptions last 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.