Can I Run Qwen3.8 27B on AMD Radeon RX 7900 XT?
Written by Jakub Rusinowski · Last updated September 6, 2026
Yes, but it's tight. Qwen3.8 27B needs 18.3 GB at 8K context (16.8 GB weights + 1.5 GB KV cache/overhead) at Q4_K_M and the AMD Radeon RX 7900 XT has 20 GB, leaving about 1.7 GB of headroom, at roughly 27 tok/s (estimated) with room for up to 32K of context.
See what else this hardware can run →
The numbers
| Model | Qwen3.8 27B |
| Parameters | 27B |
| Quantization | Q4_K_M |
| VRAM needed (8K context) | 18.3 GB |
| AMD Radeon RX 7900 XT VRAM | 20 GB |
| Verdict | Runs |
| Max context | 32K |
| Estimated speed | ~27 tok/s |
Qwen3.8 27B on the AMD Radeon RX 7900 XT: VRAM by quantization
| Quant | VRAM needed | Fits 20 GB? | Max context | Whole PC |
|---|---|---|---|---|
| F16 | 57.1 GB | ✗ No | — | — |
| Q8_0 | 31 GB | ✗ No | — | Build for this |
| Q6_K | 24.3 GB | ✗ No | — | — |
| Q5_K_M | 21.2 GB | ✗ No | — | Build for this |
| Q4_K_M | 18.3 GB | ✓ Yes | 32K | Build for this |
| Q3_K_M | 13.3 GB | ✓ Yes | 64K | — |
| Q2_K | 10.6 GB | ✓ Yes | 128K | — |
Assumes an 8K-token context with an f16 KV cache. A longer window needs more; a quantized KV cache needs less. “Max context” is the largest window that still fits in 20 GB. Figures are estimates from parameter count, quantization and memory bandwidth — the analyzer lets you tune KV-cache quant and context.
Context costs VRAM too. At Q4_K_M on the AMD Radeon RX 7900 XT: 8K 18.3 GB · 32K 19.9 GB · 128K 26.3 GB ✗. Past 128K it no longer fits 20 GB — a q8_0 KV cache buys roughly half of that back, which the calculator will price for you.
What to do next
Nothing to change — run it at Q4_K_M. If you want more capability, check whether the next size up also fits.
No compatible GPU? Qwen3.8 27B on 16 GB of system RAM, CPU only: runs.
Running Qwen3.8 27B on this card:
At 2 hrs/day, buying (~$899) beats renting at $0.34/hr after about 3.7 years.
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Cloud rates verified 2026-07 — estimates, and marketplace prices vary. Buying price is GPU MSRP only, not a full PC.
Other Qwen3.8 sizes on the AMD Radeon RX 7900 XT
- Qwen3.8-Max — does not fit (1457.5 GB)
- Qwen3.8-Flash-Next — does not fit (109.7 GB)
Qwen3.8 27B on nearby hardware
- Apple M1 (16 GB) — runs at a lower quant
- NVIDIA GeForce RTX 4090 (24 GB) — runs
All Qwen3.8 sizes on the AMD Radeon RX 7900 XT | Qwen3.8 27B model page | AMD Radeon RX 7900 XT GPU page | VRAM calculator | Check your hardware