Gemma on NVIDIA Blackwell
Can I run Gemma 3 27B on an RTX 5080?
Not at Q4_K_M — it needs 17.5 GB against 14.2 GB available. Drop to IQ3_M and it fits, at about 48.5 tokens per second.
Won't fit
17.5 GB of 14.2 GB · 123%018 GB
Weights
15.6 GB
KV cache
1.1 GB
Runtime overhead
0.8 GB
Over the limit
3.3 GB
Short by 3.3 GB. You can run it with 48 of 62 layers on the RTX 5080 and the rest in system RAM, at roughly 9.29 tok/s — usable for batch work, painful for chat. A smaller quantisation or a shorter context is usually the better trade.
Generation9.29tok/s
Prompt processing858tok/s
Max context0tokens
KV per 1K tokens0GB
Every quantisation of Gemma 3 27B on a RTX 5080
Highlighted row is the highest quality that still fits at 8K context.
| Quantisation | bpw | Weights | Total | Verdict | Max ctx | tok/s |
|---|---|---|---|---|---|---|
| FP16 / BF16 | 16.00 | 51.0 GB | 53.0 GB | Won't fit | — | 1.03 |
| INT8 / W8A8 | 8.50 | 26.8 GB | 28.7 GB | Won't fit | — | 2.65 |
| Q8_0 (GGUF) | 8.50 | 26.8 GB | 28.7 GB | Won't fit | — | 2.65 |
| FP8 (E4M3) | 8.00 | 25.5 GB | 27.4 GB | Won't fit | — | 2.85 |
| Q6_K | 6.56 | 20.9 GB | 22.9 GB | Won't fit | — | 4.25 |
| Q5_K_M | 5.67 | 18.1 GB | 20.0 GB | Won't fit | — | 6.08 |
| Q5_K_S | 5.52 | 17.6 GB | 19.5 GB | Won't fit | — | 6.51 |
| Q4_K_M | 4.85 | 15.6 GB | 17.5 GB | Won't fit | — | 9.29 |
| AWQ 4-bit | 4.25 | 15.5 GB | 17.4 GB | Won't fit | — | 9.88 |
| GPTQ 4-bit | 4.25 | 15.5 GB | 17.4 GB | Won't fit | — | 9.88 |
| MXFP4 | 4.25 | 15.5 GB | 17.4 GB | Won't fit | — | 9.88 |
| Q4_K_S | 4.58 | 14.8 GB | 16.7 GB | Won't fit | — | 11.7 |
| Q4_0 | 4.55 | 14.7 GB | 16.6 GB | Won't fit | — | 12.6 |
| IQ4_XS | 4.25 | 13.8 GB | 15.7 GB | Won't fit | — | 16.8 |
| Q3_K_M | 3.91 | 12.7 GB | 14.7 GB | Won't fit | 3K | 27.8 |
| IQ3_M | 3.70 | 12.1 GB | 14.0 GB | Fits, but tight | 10K | 48.5 |
| IQ3_XXS | 3.06 | 10.2 GB | 12.1 GB | Runs comfortably | 33K | 57.0 |
| Q2_K | 2.63 | 8.9 GB | 10.8 GB | Runs comfortably | 48K | 64.5 |
| IQ2_XXS | 2.06 | 7.1 GB | 9.1 GB | Runs comfortably | 68K | 78.2 |
| IQ1_M | 1.75 | 6.2 GB | 8.1 GB | Runs comfortably | 79K | 88.4 |