Can You Run Gemma 4 on a CPU-Only PC (128GB RAM)?
Yes — best fit is Gemma 4 31B at SFP8 (8-bit) (~30.4GB) ✅ Comfortable, using 64GB of usable memory on a 128GB CPU-Only PC.
Every Gemma 4 model on this configuration
| Model | Best quant | Size | Status |
|---|---|---|---|
| Gemma 4 E2B | BF16 (16-bit) | ~8 GB | ✅ Comfortable |
| Gemma 4 E4B | BF16 (16-bit) | ~15 GB | ✅ Comfortable |
| Gemma 4 12B | BF16 (16-bit) | ~26.7 GB | ✅ Comfortable |
| Gemma 4 26B A4B | BF16 (16-bit) | ~48 GB | ✅ Comfortable |
| Gemma 4 31B | SFP8 (8-bit) | ~30.4 GB | ✅ Comfortable |
How we got this verdict
128 ÷ 2 = 64GB usable (the RAM-÷-2 rule: one copy of the weights, one copy for working memory).
Because CPU-Only PC has enough RAM to spare, 31B fits at SFP8 (8-bit)— a higher-precision quant than most setups get. You don't need the 4-bit QAT build here, though it's still a safe download if you want a smaller file for a second model running alongside it.
Adding a discrete NVIDIA GPU is usually a bigger lever than more system RAM — it unlocks GPU offload and much faster tokens/sec, on top of whatever the RAM ÷ 2 rule already gives you here. See the GPU pages if a card is on the table.
Try a different configuration
Best fit: Gemma 4 31B · SFP8 (8-bit) · ~30.4 GB ✅ Comfortable
FAQ
Can a CPU-Only PC (128GB RAM) run the 31B flagship model?
Yes, comfortably — Gemma 4 31B fits at SFP8 (8-bit) (~30.4GB), using 64GB of usable memory on this configuration.
What's the best Gemma 4 model for a CPU-Only PC (128GB RAM)?
Gemma 4 31B at SFP8 (8-bit) (~30.4GB) is the best fit — it's the largest model that runs comfortably within the 64GB of usable memory here.
What if I have more or less memory than 128GB RAM?
This is the top configuration in this family — every Gemma 4 model already fits at its best available quant. With less (e.g. 64GB), the best-fitting model gets smaller or tighter — see the CPU-Only PC page.