Granite 4.2 8B VRAM requirements

Granite 4.2 8B has 8.8B parameters. With an 8K-token context and one request it needs about 7.32 GB of GPU memory at Q4_K_M, 10.9 GB at FP8 and 19.9 GB at FP16/BF16. The published weights take 16.4 GB (BF16). The smallest setup here that holds it at Q4_K_M with an 8K context is the RTX 4060 8GB; on one 24 GB RTX 3090 / 4090 it runs with up to 101K tokens of context.

7.32 GB at Q4_K_M, 8K context, one request

FP8
10.9 GB
FP16 / BF16
19.9 GB
Published weights
16.4 GB
Smallest setup, Q4_K_M
RTX 4060 8GB
Open Granite 4.2 8B in the calculator

Worked example: Granite 4.2 8B with 32K tokens

Inputs: Granite 4.2 8B · Q4_K_M weights · 32,768 tokens of context · one request · FP16 KV cache

Weights (8.8B at Q4_K_M)
4.95 GB
KV cache (160 KB per token)
5.00 GB
Buffers and runtime (0.5 GB + 10%)
1.50 GB
Total
11.4 GB

The smallest setup here that holds it is the RTX 3060 12GB, with about 564 MB to spare. Change the inputs in the calculator

What makes Granite 4.2 8B's memory use different

Per token of context it adds 160 KB of FP16 cache; Qwen3 8B (8.2B), the nearest-sized model here with plain full attention, adds 144 KB, so Granite 4.2 8B needs 11% more.

How much VRAM does Granite 4.2 8B need?

Granite 4.2 8B needs 7.32 GB at Q4_K_M, 11.4 GB at Q8_0 and 19.9 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.

PrecisionWeightsTotalSmallest setup
As published (BF16) 16.4 GB 19.9 GB RTX 3090 (24 GB)
FP16 / BF16 16.4 GB 19.9 GB RTX 3090 (24 GB)
FP8 / INT8 8.19 GB 10.9 GB RTX 3060 12GB
INT4 (AWQ / GPTQ) 4.35 GB 6.66 GB RTX 4060 8GB
GGUF Q8_0 8.70 GB 11.4 GB RTX 3060 12GB
GGUF Q6_K 6.71 GB 9.26 GB RTX 3060 12GB
GGUF Q5_K_M 5.80 GB 8.26 GB RTX 3060 12GB
GGUF Q4_K_M 4.95 GB 7.32 GB RTX 4060 8GB
GGUF IQ4_XS 4.45 GB 6.77 GB RTX 4060 8GB
GGUF Q3_K_M 4.00 GB 6.28 GB RTX 4060 8GB
GGUF IQ3_XXS 3.38 GB 5.59 GB RTX 4060 8GB
GGUF Q2_K 3.43 GB 5.65 GB RTX 4060 8GB

Fine-tuning Granite 4.2 8B? Granite 4.2 8B VRAM for LoRA, QLoRA and full training.

Granite 4.2 8B GGUF files on Hugging Face

The 8 GGUF files llama.cpp picks for Granite 4.2 8B 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.

QuantFileSizevs estimate 8K32K128K
Q2_K bartowski/granite-4.2-8b-GGUF 3.33 GB3,577,463,200 bytes −3% 5.54 GB9.66 GB26.2 GB
Q3_K_M bartowski/granite-4.2-8b-GGUF 4.18 GB4,487,561,632 bytes +4% 6.47 GB10.6 GB27.1 GB
IQ4_XS bartowski/granite-4.2-8b-GGUF 4.60 GB4,939,563,424 bytes +3% 6.94 GB11.1 GB27.6 GB
Q4_K_M bartowski/granite-4.2-8b-GGUF 5.16 GB5,539,283,360 bytes +4% 7.55 GB11.7 GB28.2 GB
Q5_K_M bartowski/granite-4.2-8b-GGUF 5.97 GB6,409,863,584 bytes +3% 8.44 GB12.6 GB29.1 GB
Q6_K bartowski/granite-4.2-8b-GGUF 7.00 GB7,521,223,072 bytes +4% 9.58 GB13.7 GB30.2 GB
Q8_0 bartowski/granite-4.2-8b-GGUF 8.70 GB9,345,614,240 bytes ±0% 11.4 GB15.6 GB32.1 GB
BF16 bartowski/granite-4.2-8b-GGUF 16.4 GB17,587,421,312 bytes ±0% 19.9 GB24.0 GB40.5 GB

GB here is GiB (1024³ bytes), as everywhere on this site; Hugging Face shows the Q4_K_M file as 5.5 GB, in 10⁹ bytes.

Which Granite 4.2 8B 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 (5.16 GB). One request, FP16 KV cache.

HardwareLargest GGUF, 8KIts longest contextQ4_K_M, longest context
RTX 5060 Ti 16GB Q8_0, 8.70 GB 31K 54K
RTX 4090 (24 GB) BF16, 16.4 GB 28K 100K
RTX 5090 (32 GB) BF16, 16.4 GB 75K 128K (full)
L40S (48 GB) BF16, 16.4 GB 128K (full) 128K (full)
H100 SXM (80 GB) BF16, 16.4 GB 128K (full) 128K (full)
M4 Pro Mac (64 GB, 48 GB usable) BF16, 16.4 GB 128K (full) 128K (full)
M4 Max Mac (128 GB, 96 GB usable) BF16, 16.4 GB 128K (full) 128K (full)

Run Granite 4.2 8B with llama.cpp or Ollama

llama-server -hf bartowski/granite-4.2-8b-GGUF:Q4_K_M -c 102400

granite-4.2-8b-Q4_K_M.gguf, 5.5 GB, from bartowski/granite-4.2-8b-GGUF (checked 2026-09-29). On a 24 GB RTX 3090 / 4090, Q4_K_M with -c 102400 takes 23.4 GB and leaves 653 MB.

ollama run granite4.2:8b

Ollama library tag granite4.2:8b; its quant is Ollama's choice. Same context: /set parameter num_ctx 102400.

Granite 4.2 8B at 8K, 32K and 128K (full) tokens of context

All 40 layers use full attention. Each extra token of context adds 160 KB of FP16 cache per request. 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.

ContextKV cache, FP16Total at Q4_K_MTotal at Q8_0Smallest setup, Q4_K_M
8K tokens 1.25 GB 7.32 GB 11.4 GB RTX 4060 8GB
32K tokens 5.00 GB 11.4 GB 15.6 GB RTX 3060 12GB
128K tokens 20.0 GB 27.9 GB 32.1 GB RTX 5090 (32 GB)

How fast Granite 4.2 8B writes

Tokens per second for one request with 8,192 tokens of context, estimated from memory bandwidth. A dash means it does not fit on one card. Try other settings in the speed calculator.

HardwareBandwidthQ4_K_MFP8
RTX 3060 12GB 360 GB/s 28–4019–26
RTX 4090 1,008 GB/s 74–10751–72
RTX 5090 1,792 GB/s 121–18385–124
M4 Max Mac (128 GB) 546 GB/s 42–6028–40
M3 Ultra Mac Studio (512 GB) 819 GB/s 61–8842–59
H100 SXM 3,350 GB/s 195–317143–221
H200 4,800 GB/s 249–425187–302

Longest context on one GPU

How many tokens of context Granite 4.2 8B 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.

GPUMemoryQ4_K_MQ8_0FP8
RTX 3060 12 GB 32K8K11K
RTX 4060 Ti 16GB 16 GB 55K31K34K
RTX 3090 / 4090 24 GB 101K77K81K
RTX 5090 32 GB 128K (full)124K127K
A100 40GB 40 GB 128K (full)128K (full)128K (full)
Mac, 64 GB unified memory 48 GB 128K (full)128K (full)128K (full)
L40S / RTX 6000 Ada 48 GB 128K (full)128K (full)128K (full)
A100 / H100 80GB 80 GB 128K (full)128K (full)128K (full)
Mac, 128 GB unified memory 96 GB 128K (full)128K (full)128K (full)
H200 141 GB 128K (full)128K (full)128K (full)
B200 180 GB 128K (full)128K (full)128K (full)

Model details

Parameters
8.8B (8,791,592,960)
Layers
All 40 layers use full attention
Attention cache
8 KV heads × 128
Context length
131,072 tokens
Published weights
16.4 GB (BF16)
On Hugging Face
ibm-granite/granite-4.2-8b

Why this estimate looks this way

At Q4_K_M and an 8K-token context, Granite 4.2 8B uses 4.95 GB for weights, 1.25 GB for its FP16 KV cache and 1.12 GB for estimated runtime overhead, totaling 7.32 GB. The overhead is a 0.5 GB base plus 10% of weights and cache.

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.

Granite 4.2 8B 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.

ModelParametersTotalKV per tokenSmallest setup
Granite 4.2 8B 8.8B 7.32 GB 160 KB RTX 4060 8GB
LFM2.5 8B-A1B 8.5B, 1.5B active 5.85 GB 12 KB RTX 4060 8GB
Ornith 1.0 9B 9.4B 6.61 GB 32 KB RTX 4060 8GB
MiMo V2.6 Distill Qwen 9B 9.4B 6.61 GB 32 KB RTX 4060 8GB

Granite 4.2 8B VRAM questions

How much VRAM do I need to run Granite 4.2 8B locally?

About 7.32 GB at Q4_K_M with an 8K context and one request, by the bits-per-weight estimate, and 19.9 GB at BF16. The Q4_K_M GGUF granite-4.2-8b-Q4_K_M.gguf in bartowski/granite-4.2-8b-GGUF is 5,539,283,360 bytes (5.16 GB); with an 8K context it needs 7.55 GB. The smallest setup listed here that holds Q4_K_M is the RTX 4060 8GB.

Can I run Granite 4.2 8B 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 BF16 (16.4 GB), with up to 28K tokens of context. Q4_K_M (5.16 GB) runs with up to 100K tokens of context.

Which quantization of Granite 4.2 8B 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 Q8_0 (8.70 GB), with up to 31K tokens of context. Q4_K_M (5.16 GB) runs with up to 54K tokens of context.

Can I run Granite 4.2 8B 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 BF16 (16.4 GB), with its full 128K-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 (16.4 GB), with its full 128K-token context. By default macOS lets the GPU use about 75% of unified memory.

How much more VRAM does Granite 4.2 8B need for 32K or 128K tokens of context?

Its FP16 KV cache is 1.25 GB at 8K, 5.00 GB at 32K, 20.0 GB at 128K for one request, so 128K adds 18.8 GB over 8K, plus 10% overhead. A q8_0 cache (-ctk q8_0 -ctv q8_0) takes 10.0 GB at 128K.

Why does Granite 4.2 8B use more VRAM than its GGUF file size?

The file holds only the weights. At Q4_K_M with an 8K context: 5.16 GB of weights (the file's 5,539,283,360 bytes) + 1.25 GB of FP16 KV cache + 1.14 GB of compute buffers and runtime (0.5 GB + 10%) = 7.55 GB.

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.

Granite 4.2 8B VRAM: 7.32 GB at Q4_K_M, 8K context

Numbers read from the model files on Hugging Face on . Compare it with other models in the reproducible model and GPU report.