Gemma 4 26B-A4B VRAM requirements
Gemma 4 26B-A4B needs about 17.0 GB of VRAM at Q4_K_M with 8K context, so it fits a 24 GB card such as the RTX 3090 or the RTX 4090. Gemma 4 26B-A4B has 25.8B parameters, of which about 4B are used per token; all 128 experts still have to be in memory. With the same 8K context and one request it needs 27.4 GB at FP8 and 53.9 GB at FP16/BF16. The published weights take 48.1 GB (BF16). The smallest setup here that holds it at Q4_K_M with an 8K context is the RTX 3090 (24 GB), which runs it with its full 256K-token context.
17.0 GB at Q4_K_M, 8K context, one request
- FP8
- 27.4 GB
- FP16 / BF16
- 53.9 GB
- Published weights
- 48.1 GB
- Smallest setup, Q4_K_M
- RTX 3090 (24 GB)
Worked example: Gemma 4 26B-A4B with 32K tokens
Inputs: Gemma 4 26B-A4B · Q4_K_M weights · 32,768 tokens of context · one request · FP16 KV cache
- Weights (25.8B at Q4_K_M)
- 14.5 GB
- KV cache (20 KB per token)
- 940 MB
- Buffers and runtime (0.5 GB + 10%)
- 2.05 GB
- Total
- 17.5 GB
The smallest setup here that holds it is the RTX 3090 (24 GB), with about 6.50 GB to spare. Change the inputs in the calculator
Can I run Gemma 4 26B-A4B on…
- RTX 4090: Yes, up to Q6_K
- RTX 3090: Yes, up to Q6_K
- RTX 5090: Yes, up to Q8_0
- RTX 3060 12GB: --n-cpu-moe 12
- RTX 4060 Ti 16GB: Only Q3_K_M
- RTX 5060 Ti 16GB: Only Q3_K_M
- RTX 4070 12GB: --n-cpu-moe 12
- RTX 5080 16GB: Only Q3_K_M
- RTX 4080 Super 16GB: Only Q3_K_M
- RX 7900 XTX: Yes, up to Q6_K
What makes Gemma 4 26B-A4B's memory use different
Its 25 sliding-window layers keep only the last 1,024 tokens (llama.cpp gives them 1,536 cells: the window plus a 512-token batch, rounded up to 256): at its 256K limit they hold 300 MB of cache instead of the 50.0 GB they would need with full attention.
Per token of context it adds 20 KB of FP16 cache; Granite 4.2 30B (29.3B), the nearest-sized model here with plain full attention, adds 256 KB, so Gemma 4 26B-A4B needs 8% as much.
As a mixture-of-experts model it reads about 2.25 GB of its 14.5 GB Q4_K_M weights per generated token (16%), so it writes like a much smaller model while needing memory for all of them.
Running Gemma 4 26B-A4B with experts in system RAM
llama.cpp's --n-cpu-moe N keeps the experts of the first N layers in RAM. For the measured
UD-Q4_K_M GGUF with 32K tokens of context, the smallest N
that fits each card, and the speed with 89.6 GB/s of system RAM.
Plan the offload for another GPU.
The VRAM here can sit below the 17.5 GB of the worked example because it counts the file's measured
bytes, keeps the input embedding (token_embd) in system RAM as llama.cpp does and adds a flat 1 GB of buffers, where the
estimate above adds 0.5 GB plus 10% to the preset's weights.
| GPU | --n-cpu-moe | VRAM used | In system RAM | Tokens/s |
|---|---|---|---|---|
| RTX 5060 Ti 16GB 16 GB | 3 | 15.6 GB | 2.06 GB | 32–54 |
| RTX 4090 24 GB | 0 (all on the GPU) | 17.0 GB | 748 MB | 73–128 |
| RTX 5090 32 GB | 0 (all on the GPU) | 17.0 GB | 748 MB | 120–217 |
In system RAM counts the offloaded experts plus the input embedding (token_embd), which stays in RAM even with --n-cpu-moe 0.
How much VRAM does Gemma 4 26B-A4B need?
Gemma 4 26B-A4B needs 17.0 GB at Q4_K_M, 29.1 GB at Q8_0 and 53.9 GB at FP16 with 8,192 tokens of context and one request. Each total below is the weights plus the FP16 KV cache and the runtime overhead (0.5 GB plus 10%), and each row opens the calculator with that setting. What the GGUF names mean.
| Precision | Weights | Total | Smallest setup |
|---|---|---|---|
| As published (BF16) | 48.1 GB | 53.9 GB | 2× RTX 5090 (64 GB) |
| FP16 / BF16 | 48.1 GB | 53.9 GB | 2× RTX 5090 (64 GB) |
| FP8 / INT8 | 24.0 GB | 27.4 GB | RTX 5090 (32 GB) |
| INT4 (AWQ / GPTQ) | 12.8 GB | 15.0 GB | RTX 4060 Ti 16GB |
| GGUF Q8_0 | 25.5 GB | 29.1 GB | RTX 5090 (32 GB) |
| GGUF Q6_K | 19.7 GB | 22.7 GB | RTX 3090 (24 GB) |
| GGUF Q5_K_M | 17.0 GB | 19.7 GB | RTX 3090 (24 GB) |
| GGUF Q4_K_M | 14.5 GB | 17.0 GB | RTX 3090 (24 GB) |
| GGUF IQ4_XS | 13.1 GB | 15.4 GB | RTX 4060 Ti 16GB |
| GGUF Q3_K_M | 11.7 GB | 13.9 GB | RTX 4060 Ti 16GB |
| GGUF IQ3_XXS | 9.91 GB | 11.9 GB | RTX 3060 12GB |
| GGUF Q2_K | 10.1 GB | 12.1 GB | RTX 4060 Ti 16GB |
Fine-tuning Gemma 4 26B-A4B? Gemma 4 26B-A4B VRAM for LoRA, QLoRA and full training.
Gemma 4 26B-A4B GGUF files on Hugging Face
The 8 GGUF files llama.cpp picks for Gemma 4 26B-A4B with -hf <repo>:<QUANT>, with the bytes the Hugging Face file list reported on 2026-09-29. Each total is that file plus the FP16 KV cache and 0.5 GB + 10%, one request. "vs estimate" compares the file with the bits-per-weight size the table above uses.
| Quant | File | Size | vs estimate | 8K | 32K | 128K |
|---|---|---|---|---|---|---|
| Q2_K | bartowski/ | 10.2 GB10,951,927,936 bytes | +1% | 12.2 GB | 12.7 GB | 14.8 GB |
| Q3_K_M | unsloth/ | 11.9 GB12,728,497,888 bytes | +1% | 14.0 GB | 14.5 GB | 16.6 GB |
| IQ4_XS | unsloth/ | 12.7 GB13,597,177,568 bytes | −3% | 14.9 GB | 15.4 GB | 17.5 GB |
| Q4_K_M | unsloth/ | 15.8 GB16,947,541,728 bytes | +9% | 18.4 GB | 18.9 GB | 20.9 GB |
| Q5_K_M | unsloth/ | 19.7 GB21,150,365,408 bytes | +16% | 22.7 GB | 23.2 GB | 25.2 GB |
| Q6_K | unsloth/ | 21.6 GB23,172,478,688 bytes | +10% | 24.7 GB | 25.2 GB | 27.3 GB |
| Q8_0 | ggml-org/ | 25.0 GB26,859,860,992 bytes | −2% | 28.5 GB | 29.0 GB | 31.1 GB |
| BF16 | ggml-org/ | 47.0 GB50,505,137,152 bytes | −2% | 52.7 GB | 53.2 GB | 55.3 GB |
GB here is GiB (1024³ bytes), as everywhere on this site; Hugging Face shows the Q4_K_M file as 16.9 GB, in 10⁹ bytes.
Which Gemma 4 26B-A4B GGUF fits a 16, 24, 32, 48 or 80 GB GPU or a Mac
From the file sizes above: the largest file that fits each machine with an 8K context and 0.5 GB left free, the longest context it then has room for, and the longest context for Q4_K_M (15.8 GB). One request, FP16 KV cache, -np 1. Where nothing fits, the --n-cpu-moe table above keeps experts in system RAM.
| Hardware | Largest GGUF, 8K | Its longest context | Q4_K_M, longest context |
|---|---|---|---|
| RTX 5060 Ti 16GB | IQ4_XS, 12.7 GB | 34K | No |
| RTX 4090 (24 GB) | Q5_K_M, 19.7 GB | 46K | 247K |
| RTX 5090 (32 GB) | Q8_0, 25.0 GB | 146K | 256K (full) |
| L40S (48 GB) | Q8_0, 25.0 GB | 256K (full) | 256K (full) |
| H100 SXM (80 GB) | BF16, 47.0 GB | 256K (full) | 256K (full) |
| M4 Pro Mac (64 GB, 48 GB usable) | Q8_0, 25.0 GB | 256K (full) | 256K (full) |
| M4 Max Mac (128 GB, 96 GB usable) | BF16, 47.0 GB | 256K (full) | 256K (full) |
Run Gemma 4 26B-A4B with llama.cpp or Ollama
llama-server -hf unsloth/gemma-4-26B-A4B-it-GGUF:Q4_K_M -c 252928 -np 1 gemma-4-26B-A4B-it-UD-Q4_K_M.gguf, 16.9 GB, from unsloth/
ollama run gemma4:26b
Ollama library tag gemma4:26b; its quant is Ollama's choice. Same context: /set parameter num_ctx 252928.
Gemma 4 26B-A4B at 8K, 32K, 128K and 256K (full) tokens of context
5 of its 30 layers use full attention and 25 keep a sliding window of 1,024 tokens. Each extra token of context adds 20 KB of FP16 cache per request once the sliding windows are full. The last column is the smallest setup here, one card or a group, that holds it at Q4_K_M. How the KV cache works.
| Context | KV cache, FP16 | Total at Q4_K_M | Total at Q8_0 | Smallest setup, Q4_K_M |
|---|---|---|---|---|
| 8K tokens | 460 MB | 17.0 GB | 29.1 GB | RTX 3090 (24 GB) |
| 32K tokens | 940 MB | 17.5 GB | 29.6 GB | RTX 3090 (24 GB) |
| 128K tokens | 2.79 GB | 19.6 GB | 31.7 GB | RTX 3090 (24 GB) |
| 256K tokens | 5.29 GB | 22.3 GB | 34.4 GB | RTX 3090 (24 GB) |
How fast Gemma 4 26B-A4B writes
Tokens per second for one request with 8,192 tokens of context, estimated from memory bandwidth and the parameters read per token. A dash means it does not fit on one card. Try other settings in the speed calculator.
| Hardware | Bandwidth | Q4_K_M | FP8 |
|---|---|---|---|
| RTX 3060 12GB | 360 GB/s | — | — |
| RTX 4090 | 1,008 GB/s | 90–160 | — |
| RTX 5090 | 1,792 GB/s | 145–267 | 102–182 |
| M4 Max Mac (128 GB) | 546 GB/s | 52–90 | 35–59 |
| M3 Ultra Mac Studio (512 GB) | 819 GB/s | 75–132 | 51–87 |
| H100 SXM | 3,350 GB/s | 228–448 | 168–315 |
| H200 | 4,800 GB/s | 284–585 | 217–422 |
Longest context on one GPU
How many tokens of context Gemma 4 26B-A4B fits on a single card with one request, an FP16 KV cache and 0.5 GB left free. "Full" means the model's whole context window fits.
| GPU | Memory | Q4_K_M | Q8_0 | FP8 |
|---|---|---|---|---|
| RTX 3060 | 12 GB | No | No | No |
| RTX 4060 Ti 16GB | 16 GB | No | No | No |
| RTX 3090 / 4090 | 24 GB | 256K (full) | No | No |
| RTX 5090 | 32 GB | 256K (full) | 120K | 197K |
| A100 40GB | 40 GB | 256K (full) | 256K (full) | 256K (full) |
| Mac, 64 GB unified memory | 48 GB | 256K (full) | 256K (full) | 256K (full) |
| L40S / RTX 6000 Ada | 48 GB | 256K (full) | 256K (full) | 256K (full) |
| A100 / H100 80GB | 80 GB | 256K (full) | 256K (full) | 256K (full) |
| Mac, 128 GB unified memory | 96 GB | 256K (full) | 256K (full) | 256K (full) |
| H200 | 141 GB | 256K (full) | 256K (full) | 256K (full) |
| B200 | 180 GB | 256K (full) | 256K (full) | 256K (full) |
Model details
- Parameters
- 25.8B (25,805,936,206)
- Experts
- 128 routed experts, all loaded
- Active per token
- 4B
- Layers
- 5 of its 30 layers use full attention and 25 keep a sliding window of 1,024 tokens
- Attention cache
- 2 KV heads × 512 (values come from the key projection but are cached separately)
- Sliding-window layers
- 8 KV heads × 256
- Context length
- 262,144 tokens
- Published weights
- 48.1 GB (BF16)
- On Hugging Face
- google/
gemma-4-26B-A4B-it
Why this estimate looks this way
At Q4_K_M and an 8K-token context, Gemma 4 26B-A4B uses 14.5 GB for weights, 460 MB for its FP16 KV cache and 2.00 GB for estimated runtime overhead, totaling 17.0 GB. The overhead is a 0.5 GB base plus 10% of weights and cache.
This is a mixture-of-experts model: all 128 experts contribute to the 25.8B parameters held in memory, even though only about 4B parameters run per token. Using only active parameters would understate VRAM.
Its attention layout matters for long context: 5 of its 30 layers use full attention and 25 keep a sliding window of 1,024 tokens. The FP16 cache grows by about 20 KB per additional token per request once the sliding windows are full.
The architecture and published checkpoint size come from the model's config.json and weight files. These are estimates rather than measured peak memory; inference engines can reserve extra buffers or preallocate the full configured cache.
Gemma 4 26B-A4B next to similar-sized models
The three models here closest to it in parameter count, at Q4_K_M with 8,192 tokens of context.
| Model | Parameters | Total | KV per token | Smallest setup |
|---|---|---|---|---|
| Gemma 4 26B-A4B | 25.8B, 4B active | 17.0 GB | 20 KB | RTX 3090 (24 GB) |
| Hemmingway-1 27B | 27.3B | 18.0 GB | 64 KB | RTX 3090 (24 GB) |
| ThinkingCap Qwen3.8 27B | 27.8B | 18.3 GB | 64 KB | RTX 3090 (24 GB) |
| Qwen3.6 27B | 27.8B | 18.3 GB | 64 KB | RTX 3090 (24 GB) |
Gemma 4 26B-A4B VRAM questions
How much VRAM do I need to run Gemma 4 26B-A4B locally?
About 17.0 GB at Q4_K_M with an 8K context and one request, by the bits-per-weight estimate, and 53.9 GB at BF16. The Q4_K_M GGUF gemma-4-26B-A4B-it-UD-Q4_K_M.gguf in unsloth/
Can I run Gemma 4 26B-A4B on a 24 GB GPU?
Yes. On the RTX 4090 (24 GB), the largest listed GGUF that fits with an 8K context and 0.5 GB free is Q5_K_M (19.7 GB), with up to 46K tokens of context. Q4_K_M (15.8 GB) runs with up to 247K tokens of context.
Which quantization of Gemma 4 26B-A4B fits in 16 GB of VRAM?
On the RTX 5060 Ti 16GB, the largest listed GGUF that fits with an 8K context and 0.5 GB free is IQ4_XS (12.7 GB), with up to 34K tokens of context.
Can I run Gemma 4 26B-A4B on a Mac?
On the M4 Pro Mac (64 GB, 48 GB usable), the largest listed GGUF that fits with an 8K context and 0.5 GB free is Q8_0 (25.0 GB), with its full 256K-token context. On the M4 Max Mac (128 GB, 96 GB usable), the largest listed GGUF that fits with an 8K context and 0.5 GB free is BF16 (47.0 GB), with its full 256K-token context. By default macOS lets the GPU use about 75% of unified memory.
How much more VRAM does Gemma 4 26B-A4B need for 32K or 128K tokens of context?
Its FP16 KV cache is 460 MB at 8K, 940 MB at 32K, 2.79 GB at 128K for one request, so 128K adds 2.34 GB over 8K, plus 10% overhead. A q8_0 cache
Why does Gemma 4 26B-A4B use more VRAM than its GGUF file size?
The file holds only the weights. At Q4_K_M with an 8K context: 15.8 GB of weights (the file's 16,947,541,728 bytes) + 460 MB of FP16 KV cache + 2.12 GB of compute buffers and runtime (0.5 GB + 10%) = 18.4 GB.
Does Gemma 4 26B-A4B need less VRAM because only 4B parameters are active?
No. All 128 experts stay loaded, so the Q4_K_M file takes 15.8 GB. The active parameters decide speed: each generated token reads about 2.25 GB of them.
Badge for your model card
Paste it into a Hugging Face or GitHub README; it shows the Q4_K_M total above and links to this page. Q8_0 and FP16 badges.
Numbers read from the model files on Hugging Face on . Compare it with other models in the reproducible model and GPU report.