ERNIE 4.5 300B-A47B (文心) on L40S 48GB (48GB) — VRAM, KV Cache & Throughput
ERNIE 4.5 300B-A47B (文心) (300B total, 47B active, Sparse MoE + GQA) uses 169.72 GiB of 4-bit weights (Q4_K_M), requiring 171.98 GiB total at 8K context and 177.04 GiB at 32K on L40S 48GB (~2.5 tok/s decode).
Recommended Hardware for Current Configuration
Production Launch Commands
llama-server -hf unsloth/ERNIE-4.5-300B-A47B-PT-GGUF:Q4_K_M \ --ctx-size 8192 -ngl 999 --flash-attn
vllm serve baidu/ERNIE-4.5-300B-A47B-PT \ --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 RTX PRO 6000 Blackwell (Verified Host) | 192 GB | $3.35 / hr | $406.87 / mo | Spot / On-demand | Deploy GPU ↗ |
| Vultr ($300 Free Credit*) | 4x L40S 48GB (Dedicated Instance · $300 Credit*) | 192 GB | $6.68 / hr | $812.77 / mo | Hourly | Deploy GPU ↗ |
| Vultr Cloud GPU | 4x L40S 48GB (Dedicated Instance) | 192 GB | $6.68 / hr | $812.77 / 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) — ERNIE 4.5 300B-A47B (文心)
Engineering Sizing Notes & Optimization Playbook
Quick Hardware Verdict
A single L40S 48GB (48GB) cannot hold 4-bit ERNIE 4.5 300B-A47B (文心) (171.98 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
ERNIE 4.5 300B-A47B (文心) uses Sparse MoE + GQA (300B total, 47B active per token). Moving from 8K to 32K context expands FP16 KV cache from 1.69 GiB to 6.75 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 3.37 GiB at 32K (reducing total VRAM to 173.67 GiB).
VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)
Quantization Precision & Memory Matrix — ERNIE 4.5 300B-A47B (文心) @ 8K
| Quantization Format | Weights (GiB) | KV Cache | Total VRAM (GiB) | Decode Speed | Compatibility (L40S 48GB) | Recommended GPU | Data Source |
|---|---|---|---|---|---|---|---|
| Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) | 558.79 GiB | 1.69 GiB | 561.05 GiB (602.42 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) | 296.86 GiB | 1.69 GiB | 299.12 GiB (321.18 GB) | ~1.3 tok/s | Exceeds Available GPU Memory | Multi-GPU Required | Config-derived formula |
| GGUF Q6_K (6-bit — High Precision) (Q6_K) | 229.11 GiB | 1.69 GiB | 231.37 GiB (248.43 GB) | ~1.7 tok/s | Exceeds Available GPU Memory | Instinct MI325X 256GB (256GB) | Config-derived formula |
| GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) | 198.89 GiB | 1.69 GiB | 201.15 GiB (215.98 GB) | ~2 tok/s | Exceeds Available GPU Memory | Instinct MI325X 256GB (256GB) | Config-derived formula |
| Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) | 169.72 GiB | 1.69 GiB | 171.98 GiB (184.66 GB) | ~2.5 tok/s | Exceeds Available GPU Memory | Instinct MI300X 192GB (192GB) | Config-derived formula |
| GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) | 148.68 GiB | 1.69 GiB | 150.94 GiB (162.07 GB) | ~2.9 tok/s | Exceeds Available GPU Memory | Instinct MI300X 192GB (192GB) | Config-derived formula |
| GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) | 136.77 GiB | 1.69 GiB | 139.03 GiB (149.28 GB) | ~3.3 tok/s | Exceeds Available GPU Memory | Instinct MI300X 192GB (192GB) | Config-derived formula |
| GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) | 96.39 GiB | 1.69 GiB | 98.65 GiB (105.92 GB) | ~5.6 tok/s | Exceeds Available GPU Memory | Instinct MI300X 192GB (192GB) | Config-derived formula |
Technical Specifications & FAQ
Does ERNIE 4.5 300B-A47B (文心) fit on L40S 48GB (48GB)?
In 4-bit (Q4_K_M) at 8,192 context, ERNIE 4.5 300B-A47B (文心) requires 171.98 GiB total GPU memory (169.72 GiB weights + 1.69 GiB KV cache + 0.57 GiB runtime buffers) against 45.6 GiB usable on L40S 48GB, delivering ~2.5 tok/s decode.
How much VRAM does ERNIE 4.5 300B-A47B (文心) need at 32K context?
At 32,768 context tokens, ERNIE 4.5 300B-A47B (文心) (Sparse MoE + GQA) allocates 6.75 GiB for KV cache and state, bringing total 4-bit VRAM to 177.04 GiB (190.1 GB decimal).