How much GPU memory does GLM-5.2 need?
The official FP8 artifact is 703.74 GiB before cache and runtime workspace. vLLM's current standard recipe uses one 8-GPU H200 or H20 node; the full 1M NVIDIA recipe uses eight B200s with FP8 KV cache.
GLM-5.2 FP8 / deployment worksheet
Z.ai's official FP8 checkpoint spans 141 weight files. vLLM's supported single-node baseline uses eight H200-class GPUs; its full 1M-context baseline moves to eight B200s with FP8 KV cache.
Open the editable 8 × H200 plan →Quick answer / supported tiers
The first card proves the weight-floor failure. The next two pair the exact artifact with vLLM's supported NVIDIA topologies. The BF16 card makes the multi-node boundary explicit. Calculator targets exclude KV cache unless stated.
Artifact vs deployment
The official repositories expose the bytes to load. Z.ai's model card and configuration establish the 1M window and architecture. vLLM's maintained recipe establishes supported hardware and runtime flags.
Swipe the matrix horizontally →
| Input | Official value | What it changes | What it does not prove |
|---|---|---|---|
| FP8 artifact | 703.74 GiB · 141 files | Resident-weight floor | KV cache or runtime workspace |
| BF16 artifact | 1,403.19 GiB · 282 files | Multi-node weight floor | Throughput or interconnect cost |
| Standard FP8 | 8 × H200 · TP=8 | Supported single-node baseline | Full 1M context at every concurrency |
| Full context | 1,048,576 tokens | Native context boundary | Concurrent-sequence fit |
| Full 1M NVIDIA recipe | 8 × B200 · FP8 KV | Supported full-window topology | Your traffic-shaped capacity |
| Sparse architecture | 753.38B checkpoint parameters | Artifact and routing scale | All parameters active per token |
Artifact totals were calculated from the official Hugging Face safetensors file sizes on August 7, 2026. Hardware guidance follows the vLLM GLM-5.2 recipe updated July 12, 2026. Recheck both sources if either release changes.
Read the estimate
Eight H100s are not enough.
Their 576 GiB usable planning capacity is below the FP8 files alone.
H200 is the standard node.
The current vLLM recipe uses tensor parallel size eight for FP8.
B200 unlocks the 1M recipe.
FP8 KV cache and concurrency tuning remain part of the serving plan.
Context and cache boundary
Official configuration78 layers · 1,048,576 max positions
Compressed attention inputs512 KV LoRA rank · 64 RoPE dimensions
Standard H200 recipeFP8 KV · TP=8 · MTP=5
The calculator cards deliberately keep cache out of the numeric floor because GLM-5.2 uses sparse, compressed attention rather than a portable dense K/V-head formula. For full context, follow the runtime's reported KV capacity and tune max-num-seqs against representative long prompts.
Primary-source inputs
Checkpoint size, parameter metadata, context support, configuration, and release claims come from Z.ai's official repositories. Hardware and serving flags come from vLLM's maintained GLM-5.2 recipe—not a third-party VRAM table.
Open the GPU memory calculator → Compare DeepSeek V4 Flash hardware → Find models for smaller GPU budgets → Official GLM-5.2 model card → Official GLM-5.2 configuration → Official FP8 checkpoint inventory → Official BF16 checkpoint inventory → Official vLLM deployment recipe → GLM-5 technical report →The official FP8 artifact is 703.74 GiB before cache and runtime workspace. vLLM's current standard recipe uses one 8-GPU H200 or H20 node; the full 1M NVIDIA recipe uses eight B200s with FP8 KV cache.
Not as a straightforward full-checkpoint FP8 deployment. Eight 80 GiB-class GPUs expose 576 GiB at 90% usable memory—127.74 GiB less than the official artifact before cache or runtime reserve.
The maintained vLLM recipe specifies eight H200 GPUs and tensor parallel size eight for the standard FP8 deployment. The editable worksheet adds a transparent 20% runtime reserve while leaving cache out of the numeric floor.
vLLM's current NVIDIA recipe identifies eight B200 GPUs with FP8 KV cache. It treats max-num-seqs as the main fit control, so representative concurrent long prompts still need an OOM smoke test.
The official BF16 repository totals 1,403.19 GiB across 282 safetensors files. The official FP8 repository totals 703.74 GiB across 141 files. Neither total includes the full serving allocation.
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