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How much VRAM does GLM-5.3 755B (MoE) need at Q4_K_M? Zhipu's latest 1M flagship

GLM-5.3 755B at Q4_K_M is a ~649 GB resident deployment for 1M context, or about 209 GB with active-expert offload. Capping context to 256K drops active-only to roughly 80 GB. For most buyers the Z.ai API beats self-hosting until volume hits the hundreds of millions of tokens per month.

GLM-5.3 755B at Q4_K_M with native 1M context needs about 649 GB of VRAM with all experts resident. Z.ai's August 2026 flagship keeps the 753B-scale pool of GLM-5.2 and the same 40B active per-token budget, with the MLA attention stack carried over from 5.2. Active-expert offload drops the resident footprint to roughly 209 GB, and like GLM-5.2 the MLA key-value cache at full 1M context is the piece that won't shrink.

By TechCompare · Updated

Total VRAM required
649 GB
GLM-5.3 755B (MoE) at Q4_K_M
Weights
423 GB
755B params
KV cache
168 GB
1024K tokens, FP16 KV

Calculator

Estimated VRAM required

649 GB

755B params at Q4_K_M, 1,048,576 token context, batch 1, inference.

Weights
423 GB
KV cache
168 GB
Overhead
59.0 GB

Estimate accuracy: Weights within ~2%. KV cache within ~5% for standard GQA models, ~10% for MLA (DeepSeek). Real VRAM may vary with framework (vLLM vs llama.cpp vs Transformers), Flash Attention, and driver overhead.

Hardware that fits

No single GPU in our catalog has enough memory. Multi-GPU or CPU offload required.

How this is calculated

The 755B pool at Q4_K_M is 423 GB of weights. The MLA key-value cache across 78 layers at a 512-dim latent is 168 GB at the full 1M context. Activation and runtime overhead adds about 59 GB. Active-only loading drops resident weights to 22.4 GB while the cache stays at 168 GB, landing the total near 209 GB. That makes GLM-5.3 nearly identical to GLM-5.2 on footprint at the same context, since the cache layout is unchanged.

Verdict

The 649 GB resident total is 423 GB of Q4 weights, 168 GB of MLA KV cache at 1M, and 59 GB of overhead. Resident mode needs eight 80 GB cards or five 141 GB H200 cards with NVLink. Active-only shrinks weights to 22.4 GB while the 168 GB cache stays, dropping the total to ~209 GB, which fits dual H200s or a 384 GB unified memory box. Capping context to 256K cuts the cache to ~42 GB and active-only to about 80 GB. Z.ai's official API pricing sits in the mid-tier band, so self-hosting at this scale only wins on data residency or burst-proof capacity.

More GLM scenarios

DeepSeek V4 Pro 1.6T (MoE) at Q4_K_M
DeepSeek V4 Pro 1.6T at Q4_K_M with the full 1M-token context needs about 1012 GB of VRAM with every expert resident - this is the real shape of the model and the number to plan a deployment against.
View details ➜
Llama 4 Scout (17B/109B) at Q4_K_M
Llama 4 Scout at Q4_K_M with its native 10M context needs about 2231 GB of VRAM with all 109B params resident - that's the number you size hardware against.
View details ➜
gpt-oss 20B (MoE) at Q4_K_M
gpt-oss 20B at Q4_K_M with native 128K context needs about 19.4 GB of VRAM with all experts resident, dropping to roughly 9.3 GB with active-only weight loading.
View details ➜

Frequently asked questions

How does GLM-5.3 differ from GLM-5.2 on VRAM?
GLM-5.3 is 755B total versus GLM-5.2's 753B, with the same 40B active per token and the same 78-layer MLA attention layout. The resident totals are nearly identical: ~649 GB vs ~648 GB at Q4_K_M and 1M context. The upgrade is quality and long-context reasoning depth, not a footprint change.
Can I run GLM-5.3 on two 80 GB GPUs?
Yes, in active-only mode with context capped at 256K. The full 1M context has a 168 GB KV cache that alone exceeds what dual 80 GB cards hold alongside active weights plus overhead (~209 GB total). At 256K context the cache drops to about 42 GB and the total lands near 80 GB, which fits comfortably.