GLM-4.5 (355B-A32B) on Instinct MI300X 192GB (192GB) — VRAM, KV Cache & Throughput
GLM-4.5 (355B-A32B) (355B total, 32B active, Sparse MoE + GQA) uses 200.75 GiB of 4-bit weights (Q4_K_M), requiring 204.19 GiB total at 8K context and 212.81 GiB at 32K on Instinct MI300X 192GB (~31.8 tok/s decode).
Recommended Hardware for Current Configuration
Production Launch Commands
llama-server -hf unsloth/GLM-4.5-GGUF:Q4_K_M \ --ctx-size 8192 -ngl 999 --flash-attn
vllm serve zai-org/GLM-4.5 \ --max-model-len 8192 --gpu-memory-utilization 0.92
Cloud GPU Comparison & Rent-vs-Buy TCO
Verified public rates across RunPod, Vast.ai, Vultr, and DigitalOcean.
| Provider | Recommended Instance | Total VRAM | Hourly Rate | Monthly at Selected Hours | Billing Mode | Deploy |
|---|---|---|---|---|---|---|
| RunPod | 1x B300 288GB Blackwell Ultra (Community Cloud) | 288 GB | $6.94 / hr | $843.90 / mo | Per-second | Deploy GPU ↗ |
| Vast.ai | 2x H200 141GB SXM (Verified Host · NVL) | 282 GB | $7.74 / hr | $940.94 / mo | Spot / On-demand | Deploy GPU ↗ |
| Vultr ($300 Free Credit*) | 8x A100 80GB SXM (Dedicated Instance · $300 Credit*) | 640 GB | $19.18 / hr | $2331.80 / mo | Hourly | Deploy GPU ↗ |
| Vultr Cloud GPU | 8x A100 80GB SXM (Dedicated Instance) | 640 GB | $19.18 / hr | $2331.80 / mo | Hourly | Deploy GPU ↗ |
| DigitalOcean | 1x Instinct MI325X 256GB (Dedicated Instance) | 256 GB | $3.80 / hr | $462.08 / 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 (355B-A32B)
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
A single Instinct MI300X 192GB (192GB) cannot hold 4-bit GLM-4.5 (355B-A32B) (204.19 GiB at 8K) entirely in VRAM. Use multi-GPU tensor parallelism, offload layers to system RAM, or deploy on a larger cloud GPU.
KV Cache & Runtime Tuning
GLM-4.5 (355B-A32B) uses Sparse MoE + GQA (355B total, 32B active per token). Moving from 8K to 32K context expands FP16 KV cache from 2.88 GiB to 11.5 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 5.75 GiB at 32K (reducing total VRAM to 207.06 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Quantization Precision & Memory Matrix — GLM-4.5 (355B-A32B) @ 8K
| Quantization Format | Weights (GiB) | KV Cache | Total VRAM (GiB) | Decode Speed | Compatibility (Instinct MI300X 192GB) | Recommended GPU | Data Source |
|---|---|---|---|---|---|---|---|
| Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) | 661.24 GiB | 2.88 GiB | 664.68 GiB (713.69 GB) | ~1.2 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Official checkpoint size |
| FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) | 351.28 GiB | 2.88 GiB | 354.72 GiB (380.88 GB) | ~3.3 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF Q6_K (6-bit — High Precision) (Q6_K) | 271.11 GiB | 2.88 GiB | 274.55 GiB (294.8 GB) | ~6.3 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) | 235.31 GiB | 2.88 GiB | 238.75 GiB (256.36 GB) | ~10.6 tok/s | Exceeds Available GPU Memory | Instinct MI355X 288GB (288GB) | Config-derived formula |
| Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) | 200.75 GiB | 2.88 GiB | 204.19 GiB (219.25 GB) | ~31.8 tok/s | Exceeds Available GPU Memory | Instinct MI325X 256GB (256GB) | Config-derived formula |
| GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) | 175.87 GiB | 2.88 GiB | 179.31 GiB (192.53 GB) | ~115.4 tok/s | Fits with Safe Headroom | Instinct MI325X 256GB (256GB) | Config-derived formula |
| GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) | 161.79 GiB | 2.88 GiB | 165.23 GiB (177.41 GB) | ~122.4 tok/s | Fits with Safe Headroom | Instinct MI300X 192GB (192GB) | Config-derived formula |
| GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) | 113.97 GiB | 2.88 GiB | 117.41 GiB (126.07 GB) | ~154.1 tok/s | Fits with Safe Headroom | Instinct MI300X 192GB (192GB) | Config-derived formula |
Technical Specifications & FAQ
Does GLM-4.5 (355B-A32B) fit on Instinct MI300X 192GB (192GB)?
In 4-bit (Q4_K_M) at 8,192 context, GLM-4.5 (355B-A32B) requires 204.19 GiB total GPU memory (200.75 GiB weights + 2.88 GiB KV cache + 0.56 GiB runtime buffers) against 182.4 GiB usable on Instinct MI300X 192GB, delivering ~31.8 tok/s decode.
How much VRAM does GLM-4.5 (355B-A32B) need at 32K context?
At 32,768 context tokens, GLM-4.5 (355B-A32B) (Sparse MoE + GQA) allocates 11.5 GiB for KV cache and state, bringing total 4-bit VRAM to 212.81 GiB (228.5 GB decimal).