Can I Run Bonsai 27B on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM)?

Written by Jakub Rusinowski · Last updated July 15, 2026

Yes, but it is tight

Yes, but it is tight — 1-bit Bonsai 27B at Q8_0 needs about 31.2 GB of the 32 GB usable on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM), leaving only ~0.8 GB before the runtime starts swapping. Expect ~41.3 tok/s (estimated), with room for about 8,192 tokens of context.

Confidence: low · Recommended quantization: Q8_0 · Estimated speed: ~41.3 tok/s

RTX 5090 Desktop (32 GB VRAM, 64 GB RAM) — what it gives a model

Usable memory for models32 GB
Memory bandwidth1792 GB/s
Form factorDesktop
Operating systemWindows or Linux
Memory upgradeableYes

Bonsai 27B on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM): memory by quantization

QuantMemory neededFits 32 GB?Max contextEst. speedDownload
F1656.5 GB✗ No54 GB
Q8_031.2 GB✓ Yes8K~41.3 tok/s28.7 GB
Q6_K24.7 GB✓ Yes32K~51.6 tok/s22.1 GB
Q5_K_M21.7 GB✓ Yes32K~58.4 tok/s19.1 GB
Q4_K_M18.8 GB✓ Yes64K~66.6 tok/s16.3 GB
Q3_K_M14.1 GB✓ Yes64K~87.3 tok/s11.5 GB
Q2_K11.4 GB✓ Yes64K~105.3 tok/s8.9 GB

Which Bonsai 27B sizes fit

VariantNeeds at Q4_K_MFits?Est. speed
1-bit Bonsai 27B18.8 GB✓ Fits~66.6 tok/s
Ternary Bonsai 27B18.8 GB✓ Fits~66.6 tok/s

What to watch out for

RTX 5090 desktop limitations

Recommended setup

Ollama or llama.cpp (CUDA/ROCm) — vLLM if you need concurrent serving

How these numbers are calculated

FAQ

Can I run Bonsai 27B on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM)?

Yes, but it is tight — 1-bit Bonsai 27B at Q8_0 needs about 31.2 GB of the 32 GB usable on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM), leaving only ~0.8 GB before the runtime starts swapping. Expect ~41.3 tok/s (estimated), with room for about 8,192 tokens of context.

Which quantization of Bonsai 27B should I use on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM)?

Q8_0 — it needs about 31.2 GB of the 32 GB available, downloads as roughly 28.7 GB, and runs at an estimated 41.3 tokens/sec with up to 8K of context.

What limits Bonsai 27B on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM)?

Nothing binding — the model fits with headroom and generates at a usable speed on this hardware.

Which runtime should I use?

Ollama or llama.cpp (CUDA/ROCm) — vLLM if you need concurrent serving

Other Computers

Other Models on RTX 5090 Desktop (32 GB VRAM, 64 GB RAM)

Bonsai 27B on GPUs

What This Model Is Good At

Model & Tools

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