GLM-5.3-Flash GGUF size and VRAM requirements
unsloth/GLM-5.3-Flash-GGUF is a very large language model with 321.32 billion parameters, built on the glm5next architecture. It is released under the mit license and has been downloaded 27,288 times.
GLM-5.3-Flash-GGUF is a Mixture-of-Experts model with 288 experts, of which 8 are active on each token. Routing only 8 of 288 experts makes it noticeably faster than a dense model of the same size — but every expert still has to be held in memory, so the numbers below are set by the full parameter count, not the active one. It is built from 45 transformer layers, a hidden size of 4,096, 64 attention heads. GLM-5.3-Flash-GGUF uses Multi-head Latent Attention, caching a single compressed latent per layer instead of full keys and values. That keeps the KV cache small even at long context — the memory figures on this page already reflect it.
To run unsloth/GLM-5.3-Flash-GGUF locally at a 4,096-token context, its quantized versions need between 87.54 GB (IQ1_S, lowest quality) and 598.42 GB (BF16, highest quality) of memory, weights plus KV cache and a system margin included. Context length drives that memory directly: at 4,096 tokens the KV cache for GLM-5.3-Flash-GGUF is about 0.04 GB, rising to roughly 11.0 GB at its full 1,048,576-token context. Shorter prompts free up memory for a higher-quality quantization.
Available GGUF quantizations for unsloth/GLM-5.3-Flash-GGUF include IQ1_S, IQ1_M, IQ2_XXS, Q2_K_XL, IQ3_XXS, Q3_K_XL, IQ4_XS, Q4_K_XL, Q5_K_XL, Q6_K_XL, Q8_0, BF16. The model supports a native context length of up to 1,048,576 tokens; a longer context grows the KV cache and the memory needed.
GGUF file size and memory by quantization
Compare real GGUF weight sizes, estimated KV cache and total memory for Q4, Q5, Q8 and every quantization published in this repository.
| Quant. | Bits | Quality | Weights | KV | Total | Speed~ | Verdict |
|---|---|---|---|---|---|---|---|
| IQ1_S | 2.32 | Very low | 86.69 GB | 0.04 GB | 87.54 GB | — | Insufficient |
| IQ1_M | 2.43 | Very low | 90.88 GB | 0.04 GB | 91.72 GB | — | Insufficient |
| IQ2_XXS | 2.54 | Very low | 94.85 GB | 0.04 GB | 95.69 GB | — | Insufficient |
| Q2_K_XL | 2.71 | Low | 101.25 GB | 0.04 GB | 102.1 GB | — | Insufficient |
| IQ3_XXS | 3.0 | Low | 112.1 GB | 0.04 GB | 112.94 GB | — | Insufficient |
| Q3_K_XL | 3.67 | Fair | 137.4 GB | 0.04 GB | 138.25 GB | — | Insufficient |
| IQ4_XS | 3.9 | Fair | 146.05 GB | 0.04 GB | 146.89 GB | — | Insufficient |
| Q4_K_XL | 4.97 | Good | 185.99 GB | 0.04 GB | 186.83 GB | — | Insufficient |
| Q5_K_XL | 5.98 | Very good | 223.8 GB | 0.04 GB | 224.65 GB | — | Insufficient |
| Q6_K_XL | 7.27 | Excellent | 271.79 GB | 0.04 GB | 272.63 GB | — | Insufficient |
| Q8_0 | 8.49 | Excellent | 317.56 GB | 0.04 GB | 318.41 GB | — | Insufficient |
| BF16 | 15.97 | Excellent | 597.57 GB | 0.04 GB | 598.42 GB | — | Insufficient |
KV cache computed from the model's exact architecture. Speed is a rough estimate bounded by memory bandwidth.
Frequently asked questions
What kind of model is unsloth/GLM-5.3-Flash-GGUF?
unsloth/GLM-5.3-Flash-GGUF is a language model with 321.32 billion parameters, based on the glm5next architecture. It is released under the mit license and distributed as GGUF files for local inference.
Is unsloth/GLM-5.3-Flash-GGUF a Mixture-of-Experts (MoE) model?
Yes. unsloth/GLM-5.3-Flash-GGUF is a Mixture-of-Experts model with 288 experts, of which 8 are activated per token. That makes it faster than a dense model of the same size, but all 288 experts must be loaded into memory, so the VRAM/RAM it needs is driven by the total parameter count, not the active one.
How does unsloth/GLM-5.3-Flash-GGUF handle long context?
unsloth/GLM-5.3-Flash-GGUF uses Multi-head Latent Attention, which caches one compressed latent per layer instead of full keys and values. Its KV cache therefore grows much more slowly than a standard model of the same size, so long contexts add relatively little memory.
Can I run unsloth/GLM-5.3-Flash-GGUF on an 8 GB GPU?
No. unsloth/GLM-5.3-Flash-GGUF does not fit on an 8 GB GPU, even with the smallest quantization and system RAM offloading.
Can I run unsloth/GLM-5.3-Flash-GGUF on a 16 GB GPU?
No. unsloth/GLM-5.3-Flash-GGUF does not fit on a 16 GB GPU, even with the smallest quantization and system RAM offloading.
Can I run unsloth/GLM-5.3-Flash-GGUF on a 24 GB GPU?
No. unsloth/GLM-5.3-Flash-GGUF does not fit on a 24 GB GPU, even with the smallest quantization and system RAM offloading.
What context length does unsloth/GLM-5.3-Flash-GGUF support?
unsloth/GLM-5.3-Flash-GGUF supports a native context length of up to 1,048,576 tokens. A longer context grows the KV cache, so it increases the memory needed to run the model.
What is the best quantization for unsloth/GLM-5.3-Flash-GGUF?
For unsloth/GLM-5.3-Flash-GGUF, higher bits-per-weight means better quality. A common sweet spot is a Q4_K_M or Q5_K_M quantization, which keeps most of the quality while roughly halving the memory versus 8-bit. Pick the highest quantization that still fits in your VRAM.