Can you run GLM 5.3 Flash locally?
glm family · Aug 2026 · 321.3B parameters (18B activated per token) · Hugging Face model card
Sparse 320B/18B MoE. Q4 weights ~180 GB: needs 96 GB+ unified memory with expert offload to run at all; comfortable at 192-256 GB.
Minimum: 192 GB+ unified memory or multi-GPU workstation · Recommended: 256 GB Mac Studio / multi-GPU server
How much VRAM does GLM 5.3 Flash need at each quantization?
GLM 5.3 Flash needs 212.1 GB of VRAM at Q4_K_M. The table below lists weights-only size and total VRAM including overhead for each common quantization level with 4k and 32k token contexts.
| Quantization | Bits / weight | Weights only | Total + KV @4k ctx | Total + KV @32k ctx |
|---|---|---|---|---|
| Q4_K_M | 4.8 | 192.8 GB | 212.1 GB | 212.1 GB |
| Q5_K_M | 5.7 | 229.0 GB | 251.9 GB | 251.9 GB |
| Q6_K | 6.6 | 265.1 GB | 291.6 GB | 291.6 GB |
| Q8_0 | 8.5 | 341.4 GB | 375.6 GB | 375.6 GB |
| FP16 | 16 | 642.7 GB | 706.9 GB | 706.9 GB |
Method: weights = parameters × bits-per-weight (Q4_K_M ≈ 4.8, Q5_K_M ≈ 5.7, Q6_K ≈ 6.6, Q8_0 ≈ 8.5, FP16 = 16), plus 10% loading overhead, plus KV cache from the verified architecture config (not applicable to this architecture). Source: Z.ai GLM-5.3-Flash: 320B total / 18B active MoE (288 routed experts, top-8 + 1 shared), hybrid sparse+linear attention, 1M context, MIT. Source: z.ai/blog/glm-5.3-flash | run2 2026-09-12: params now repo-exact (safetensors 321.33B); context per Z.ai announcement; MIT license per repo card
Which GPUs can run GLM 5.3 Flash locally?
At Q4_K_M with a 4k context, GLM 5.3 Flash needs 212.1 GB of VRAM. The lists below are computed live from our GPU database and grouped by how much headroom the card has. Disclosure: CompareAIHardware.com participates in the Amazon Associates program and earns from qualifying purchases through links on this page. Affiliate relationships do not influence our recommendations.
Runs GLM 5.3 Flash comfortably (25%+ VRAM headroom)
| GPU | VRAM | Bandwidth | Type | |
|---|---|---|---|---|
| AMD Instinct MI355X | 288 GB | 8000 GB/s | Data Center GPU | |
| NVIDIA B300 (Blackwell Ultra) | 288 GB | 8000 GB/s | Data Center GPU |
Minimum GPUs that fit GLM 5.3 Flash at Q4_K_M
These GPUs hold the model but leave little headroom — keep contexts short.
| GPU | VRAM | Bandwidth | Type | |
|---|---|---|---|---|
| AMD Instinct MI325X | 256 GB | 6000 GB/s | Data Center GPU |
Needs 2+ GPUs to run GLM 5.3 Flash
One of these cards is too small on its own, but a pair (tensor or pipeline parallel, ~90% efficiency) covers the 212.1 GB requirement. See our multi-GPU guide for setup.
| GPU | VRAM | Bandwidth | Type | |
|---|---|---|---|---|
| H200 SXM | 141 GB ×2 | 4800 GB/s | Data Center GPU | |
| AMD Instinct MI300X | 192 GB ×2 | 5300 GB/s | Data Center GPU | |
| NVIDIA B200 | 192 GB ×2 | 8000 GB/s | Data Center GPU |
Can a Mac run GLM 5.3 Flash?
Yes — these Apple Silicon machines fit GLM 5.3 Flash at Q4_K_M, since macOS lets the GPU use about 75% of unified memory. Generation speed is bound by memory bandwidth, so the GB/s column matters as much as capacity.
| Apple Silicon | Unified memory | Usable by GPU (~75%) | Bandwidth |
|---|---|---|---|
| M3 Ultra (Mac Studio) | 512 GB | 384 GB | 819 GB/s |