GLM-4.5 Air (110B-A12B) on H20 141GB HBM3e (141GB) — VRAM, KV Cache & Throughput

GLM-4.5 Air (110B-A12B) (110.47B total, 12B active, Sparse MoE + GQA) uses 67.96 GiB of 4-bit weights (Q4_K_M), requiring 69.96 GiB total at 8K context and 74.27 GiB at 32K on H20 141GB HBM3e (~180.7 tok/s decode).

Interactive Sizing Workbench

Full Compatibility Report →
141 GB · 4800 GB/s
Fits with Safe Headroom
Measured GGUF shard size HF config.json ↗
Memory Allocation Breakdown (GiB) 69.96 GiB (75.12 GB) / 141 GiB (50%)
Model Weights: 67.96 GiB KV Cache & State: 1.44 GiB Runtime & Activation Buffers: 0.56 GiB System RAM Offload: 0 GiB
Required GPU Memory
69.96 GiB
75.12 GB (decimal)
Usable Hardware Memory
133.9 GiB
141 GB (physical)
Safe Headroom
+63.94 GiB
50% utilization
Est. Decode Throughput
~180.7 tok/s
12B active params
Est. Prefill Throughput
~6413 tok/s
4K Prompt TTFT: ~639 ms
Est. Cost / 1M Tokens
$0.68
Sparse MoE + GQA · MIT

Recommended Hardware for Current Configuration

Best Single GPU
RTX PRO 6000 Blackwell (96GB)
~$8,500
Best Value / Used GPU
2x A100 80GB SXM
160GB · ~$24,000
Apple Unified Memory
Ryzen AI Max+ 395 128GB
~$1,999
Cloud From
Vast.ai · $0.44 / hr
1x A100 80GB SXM

Production Launch Commands

llama.cpp (GGUF)
llama-server -hf unsloth/GLM-4.5-Air-GGUF:Q4_K_M \
  --ctx-size 8192 -ngl 999 --flash-attn
vLLM
vllm serve zai-org/GLM-4.5-Air \
  --max-model-len 8192 --gpu-memory-utilization 0.92
Live Token Speed Simulator (TTFT ~639ms · ~180.7 tok/s)
[GLM-4.5 Air (110B-A12B) · 69.96 GiB] allocated on target GPU. Prefill completed in TTFT window; streaming autoregressive tokens at memory-bandwidth-bound rate...

Cloud GPU Comparison & Rent-vs-Buy TCO

Verified public rates across RunPod, Vast.ai, Vultr, and DigitalOcean.

Verified: 2026-11-04
Purchase break-even
~64.4 months
Est. local power: $12.77 / mo
Provider Recommended Instance Total VRAM Hourly Rate Monthly at Selected Hours Billing Mode Deploy
RunPod 1x A100 80GB SXM (Community Cloud · PCIe) 80 GB $1.19 / hr $144.70 / mo Per-second Deploy GPU ↗
Vast.ai 1x A100 80GB SXM (Verified Host · SXM4) 80 GB $0.44 / hr $53.75 / mo Spot / On-demand Deploy GPU ↗
Vultr ($300 Free Credit*) 1x A100 80GB SXM (Dedicated Instance · $300 Credit*) 80 GB $2.40 / hr $291.48 / mo Hourly Deploy GPU ↗
Vultr Cloud GPU 1x A100 80GB SXM (Dedicated Instance) 80 GB $2.40 / hr $291.48 / mo Hourly Deploy GPU ↗
DigitalOcean 1x Instinct MI300X 192GB (Dedicated Instance) 192 GB $2.59 / hr $314.94 / mo Per-second Deploy GPU ↗

Rates reflect public listings on the verification date and fluctuate with regional inventory.

Fine-Tuning VRAM Requirements (QLoRA / LoRA / Full) — GLM-4.5 Air (110B-A12B)

QLoRA (4b) Fits with Safe Headroom
70.72 GiB
Model Weights: 67.96 GiB · Gradients + Optimizer: 1.68 GiB · Act: 1.08 GiB
Recommended GPU: RTX PRO 6000 Blackwell (96GB)
LoRA (16b) Exceeds Available GPU Memory
209.84 GiB
Model Weights: 205.77 GiB · Gradients + Optimizer: 2.64 GiB · Act: 1.43 GiB
Recommended GPU: Instinct MI325X 256GB (256GB)
Full BF16 Exceeds Available GPU Memory
846.18 GiB
Model Weights: 205.77 GiB · Gradients + Optimizer: 637.89 GiB · Act: 2.52 GiB
Recommended GPU: 8x H200 141GB SXM (1128GB)

Engineering Sizing Notes & Optimization Playbook

Quick Hardware Verdict

H20 141GB HBM3e (141GB physical, 133.9 GiB usable) runs 4-bit (Q4_K_M) GLM-4.5 Air (110B-A12B) at 8K context using 69.96 GiB with 63.94 GiB of safe headroom (~180.7 tok/s single-stream decode).

KV Cache & Runtime Tuning

GLM-4.5 Air (110B-A12B) uses Sparse MoE + GQA (110.47B total, 12B active per token). Moving from 8K to 32K context expands FP16 KV cache from 1.44 GiB to 5.75 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 2.87 GiB at 32K (reducing total VRAM to 71.4 GiB).

VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)

GLM-4.5 Air (110B-A12B) VRAM scaling from 4K to 128K context (4K: 69.24 GiB, 8K: 69.96 GiB, 32K: 74.27 GiB, 128K: 91.52 GiB) 4K 69.24 GiB (KV 0.72 GiB) 8K 69.96 GiB (KV 1.44 GiB) 32K 74.27 GiB (KV 5.75 GiB) 128K 91.52 GiB (KV 23 GiB) H20 141GB HBM3e (141GB)
Model weights remain constant while attention KV cache grows with context length and batch size.

Quantization Precision & Memory Matrix — GLM-4.5 Air (110B-A12B) @ 8K

Quantization Format Weights (GiB) KV Cache Total VRAM (GiB) Decode Speed Compatibility (H20 141GB HBM3e) Recommended GPU Data Source
Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) 205.77 GiB 1.44 GiB 207.77 GiB (223.09 GB) ~6.5 tok/s Exceeds Available GPU Memory Instinct MI325X 256GB (256GB) Official checkpoint size
FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) 109.39 GiB 1.44 GiB 111.39 GiB (119.6 GB) ~133.8 tok/s Fits with Safe Headroom Instinct MI300X 192GB (192GB) Measured GGUF shard size
GGUF Q6_K (6-bit — High Precision) (Q6_K) 92.21 GiB 1.44 GiB 94.21 GiB (101.16 GB) ~149.9 tok/s Fits with Safe Headroom Instinct MI300X 192GB (192GB) Measured GGUF shard size
GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) 77.78 GiB 1.44 GiB 79.78 GiB (85.66 GB) ~166.8 tok/s Fits with Safe Headroom RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) 67.96 GiB 1.44 GiB 69.96 GiB (75.12 GB) ~180.7 tok/s Fits with Safe Headroom RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) 56.33 GiB 1.44 GiB 58.33 GiB (62.63 GB) ~200.4 tok/s Fits with Safe Headroom RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) 53.28 GiB 1.44 GiB 55.28 GiB (59.36 GB) ~206.3 tok/s Fits with Safe Headroom RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size
GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) 44.19 GiB 1.44 GiB 46.19 GiB (49.6 GB) ~226.1 tok/s Fits with Safe Headroom RTX PRO 6000 Blackwell (96GB) Measured GGUF shard size

Technical Specifications & FAQ

Does GLM-4.5 Air (110B-A12B) fit on H20 141GB HBM3e (141GB)?

In 4-bit (Q4_K_M) at 8,192 context, GLM-4.5 Air (110B-A12B) requires 69.96 GiB total GPU memory (67.96 GiB weights + 1.44 GiB KV cache + 0.56 GiB runtime buffers) against 133.9 GiB usable on H20 141GB HBM3e, delivering ~180.7 tok/s decode.

How much VRAM does GLM-4.5 Air (110B-A12B) need at 32K context?

At 32,768 context tokens, GLM-4.5 Air (110B-A12B) (Sparse MoE + GQA) allocates 5.75 GiB for KV cache and state, bringing total 4-bit VRAM to 74.27 GiB (79.75 GB decimal).

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