Can an Arc B580 run Gemma 4 31B Instruct?
Partly
Not entirely. About 30 of its 60 layers fit on the card and the rest run on the CPU, which brings generation down to roughly 2.6 tokens per second.
In practice
It does not fit entirely. About 30 of the 60 layers of Gemma 4 31B Instruct fit on the Arc B580 at Q4_K_M, and the rest run on the CPU from system RAM. The estimate is about 2.6 tokens per second.
That number is lower than the share on the card suggests, and our own offload sweep shows why: every token waits for the slowest part, so the last layers left in RAM cost far more than the first ones moved. There is no quantization of this model worth using that fits entirely, so the choice is between this split and a smaller model.
The numbers
Gemma 4 31B Instruct has 31.27 billion parameters across 60 layers. The Arc B580 has 12 GB of VRAM at 456 GB/s, of which about 11.2 GB is left for a model once the operating system has taken its share.
| Quantization | Total needed | Fits | Speed |
|---|---|---|---|
| Q8_0 | 34.67 GB | partial | 1.2 t/s |
| Q6_K | 27.61 GB | partial | 1.7 t/s |
| Q5_K_M | 24.44 GB | partial | 2.0 t/s |
| Q4_K_M | 21.31 GB | partial | 2.6 t/s |
| IQ4_XS | 19.2 GB | partial | 3.2 t/s |
| Q3_K_M | 17.96 GB | partial | 3.6 t/s |
| IQ3_XXS degraded | 14.87 GB | partial | 5.9 t/s |
| Q2_K degraded | 15.93 GB | partial | 4.9 t/s |
| IQ2_XXS degraded | 11.23 GB | partial | 21.3 t/s |
Nothing on this ladder fits entirely, including the 2-bit levels we do not recommend. Rows marked partial or experts in RAM run with part of the model in system RAM, at the speed shown.
The settings we would use
llama-server -m <model>.gguf -ngl 30 -c 8192 -fa on 30 of 60 layers fit on the card. If the load fails with an out-of-memory error, lower the number by 2 and try again.
This split is set in llama.cpp. Ollama chooses its own placement and does not take these options, so run ollama ps to see what it picked.
The llama.cpp flags guide explains each option above.
If you want it faster
A smaller model from the same family is the straightforward answer. These fit on an Arc B580 at a quantization worth using:
- Gemma 3 12B Instruct, 12.19B at Q6_K, 10.52 GB, about 25.6 tokens/s
- Gemma 4 12B Instruct, 11.96B at Q6_K, 10.84 GB, about 24.8 tokens/s
- Gemma 2 9B Instruct, 9.24B at Q6_K, 9.42 GB, about 28.7 tokens/s
Shortening the context will not rescue this one: at 4k it still wants 20.06 GB against 21.31 GB at 8k, because the weights, not the cache, are what fill the card.
Models of this size are what a second GPU or a large-memory machine is for. The multi-GPU guide shows what 2 cards add, and the Mac and PC comparison shows where unified memory holds a model that no single card can.
Or the hardware that does run it
The cheapest device we track that runs Gemma 4 31B Instruct at a quantization worth using is the GeForce RTX 3090, around $700 used , running it at Q4_K_M at about 33.0 tokens per second. Check the current price (affiliate link, indicative price reviewed 2026-09-01). Compare every option.
What else an Arc B580 runs well
For comparison, these are the other popular models that fit this device at a sound quantization, best pairings first.
| Model | Quantization | Memory | Speed |
|---|---|---|---|
| Gemma 4 12B Instruct | Q6_K | 10.84 GB | 24.8 t/s |
| Qwen3.5 9B | Q8_0 | 9.25 GB | 29.3 t/s |
| Qwen3 14B | Q5_K_M | 10.96 GB | 24.6 t/s |
| Qwen3 8B | Q8_0 | 9.02 GB | 30.1 t/s |
The same model on nearby hardware
Memory decides whether Gemma 4 31B Instruct loads and bandwidth decides how quickly it answers. Here is what a step down, a card with the same memory and a step up do with it.
| Device | Memory | Bandwidth | Result |
|---|---|---|---|
| GeForce RTX 3070 | 8 GB | 448 GB/s | partial, 2.0 t/s |
| GeForce RTX 4070 | 12 GB | 504 GB/s | partial, 2.7 t/s |
| GeForce RTX 5080 | 16 GB | 960 GB/s | does not fit |
See how fast it feels
Arc B580 running Gemma 4 31B Instruct at Q4_K_M, 30 of 60 layers on the GPU
YouWhy does my model use more memory when the conversation gets longer?
Reading your question
Simulated from our estimate at a 512-token question, not a recording. Assumes nothing else is competing for the GPU.
Questions people ask
How much VRAM does Gemma 4 31B Instruct need on Arc B580?
At Q4_K_M with an 8k context window it needs 21.31 GB in total: 17.58 GB of weights, 3.28 GB of KV cache and 0.45 GB of runtime overhead. The Arc B580 makes about 11.2 GB available once the operating system has taken its share.
Can I run Gemma 4 31B Instruct on Arc B580 anyway?
Yes, with part of it in system RAM. About 30 of 60 layers fit on the card and the speed falls to roughly 2.6 tokens per second, which suits batch work better than conversation.
Keep going
Everything the Arc B580 runs, the full breakdown for Gemma 4 31B Instruct, how the numbers are made in the methodology, or a different pairing in the calculator.