GLM-5 (744B) on RTX 5080 (16GB) — VRAM, KV Cache & Throughput
GLM-5 (744B) (744B total, 40B active, Multi-head Latent Attention (MLA) MoE) uses 420.45 GiB of 4-bit weights (Q4_K_M), requiring 421.71 GiB total at 8K context and 423.76 GiB at 32K on RTX 5080 (~2.3 tok/s decode).
Recommended Hardware for Current Configuration
Production Launch Commands
llama-server -hf unsloth/GLM-5-GGUF:Q4_K_M \ --ctx-size 8192 -ngl 999 --flash-attn
vllm serve zai-org/GLM-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 | 2x B300 288GB Blackwell Ultra (Community Cloud) | 576 GB | $13.88 / hr | $1687.81 / mo | Per-second | Deploy GPU ↗ |
| Vast.ai | 8x A100 80GB SXM (Verified Host · SXM4) | 640 GB | $3.54 / hr | $429.98 / 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 | 8x Instinct MI300X 192GB (Dedicated Instance) | 1536 GB | $20.72 / hr | $2519.55 / 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-5 (744B)
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
A single RTX 5080 (16GB) cannot hold 4-bit GLM-5 (744B) (421.71 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-5 (744B) uses Multi-head Latent Attention (MLA) MoE (744B total, 40B active per token). Moving from 8K to 32K context expands FP16 KV cache from 0.69 GiB to 2.74 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 1.37 GiB at 32K (reducing total VRAM to 422.39 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Quantization Precision & Memory Matrix — GLM-5 (744B) @ 8K
| Quantization Format | Weights (GiB) | KV Cache | Total VRAM (GiB) | Decode Speed | Compatibility (RTX 5080) | Recommended GPU | Data Source |
|---|---|---|---|---|---|---|---|
| Native Weights (BF16 / FP8 / MXFP4 — Lossless) (FP8) | 1386 GiB | 0.69 GiB | 1387.26 GiB (1489.56 GB) | ~0.8 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Official checkpoint size |
| FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) | 736.21 GiB | 0.69 GiB | 737.47 GiB (791.85 GB) | ~1.3 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF Q6_K (6-bit — High Precision) (Q6_K) | 568.18 GiB | 0.69 GiB | 569.44 GiB (611.43 GB) | ~1.7 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) | 493.02 GiB | 0.69 GiB | 494.28 GiB (530.73 GB) | ~2 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) | 420.45 GiB | 0.69 GiB | 421.71 GiB (452.81 GB) | ~2.3 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) | 368.38 GiB | 0.69 GiB | 369.64 GiB (396.9 GB) | ~2.6 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) | 338.9 GiB | 0.69 GiB | 340.16 GiB (365.24 GB) | ~2.8 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) | 238.57 GiB | 0.69 GiB | 239.83 GiB (257.52 GB) | ~4 tok/s | Exceeds Available GPU Memory | Instinct MI355X 288GB (288GB) | Config-derived formula |
Technical Specifications & FAQ
Does GLM-5 (744B) fit on RTX 5080 (16GB)?
In 4-bit (Q4_K_M) at 8,192 context, GLM-5 (744B) requires 421.71 GiB total GPU memory (420.45 GiB weights + 0.69 GiB KV cache + 0.57 GiB runtime buffers) against 15.2 GiB usable on RTX 5080, delivering ~2.3 tok/s decode.
How much VRAM does GLM-5 (744B) need at 32K context?
At 32,768 context tokens, GLM-5 (744B) (Multi-head Latent Attention (MLA) MoE) allocates 2.74 GiB for KV cache and state, bringing total 4-bit VRAM to 423.76 GiB (455.01 GB decimal).