Baidu·ERNIE·Ernie4_5_MoeForCausalLM

ERNIE 4.5 21B A3B PT — Hardware Requirements & GPU Compatibility

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ERNIE 4.5 21B A3B PT is a 21B-parameter open language model from Baidu in the ERNIE family. It supports a context window of up to 131,072 tokens. At Q4_K_M it needs about 13.02 GB of VRAM — see which GPUs and Macs can run it below.

25.6K downloads 165 likes 2.5K quant downloads131K context

Specifications

Publisher
Baidu
Family
ERNIE
Parameters
21B
Architecture
Ernie4_5_MoeForCausalLM
Context Length
131,072 tokens
Vocabulary Size
103,424
Release Date
2025-06-28
License
Apache 2.0

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How Much VRAM Does ERNIE 4.5 21B A3B PT Need?

Select a quantization to see compatible GPUs below.

QuantizationBitsVRAM
Q2_K3.409.3 GB
Q3_K_S3.509.6 GB
Q3_K_M3.9010.7 GB
Q4_04.0010.9 GB
Q4_K_M4.8013.0 GB
Q5_K_M5.7015.4 GB
Q6_K6.6017.7 GB
Q8_08.0021.4 GB

Which GPUs Can Run ERNIE 4.5 21B A3B PT?

Q4_K_M · 13.0 GB

ERNIE 4.5 21B A3B PT (Q4_K_M) requires 13.0 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 17+ GB is recommended. Using the full 131K context window can add up to 7.4 GB, bringing total usage to 20.4 GB. 26 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti, NVIDIA GeForce RTX 5080.

Which Devices Can Run ERNIE 4.5 21B A3B PT?

Q4_K_M · 13.0 GB

47 devices with unified memory can run ERNIE 4.5 21B A3B PT, including NVIDIA DGX H100, NVIDIA DGX A100 640GB, Mac Mini M4 (16 GB).

Runs great

Plenty of headroom
NVIDIA DGX H100~1338 tok/sNVIDIA DGX A100 640GB~814 tok/sMac Studio (M3 Ultra, 256GB)~44 tok/sMac Studio (M3 Ultra, 512GB)~44 tok/sMac Studio (M3 Ultra, 96GB)~44 tok/sMac Pro M2 Ultra (192 GB)~43 tok/sMac Studio M2 Ultra (192 GB)~43 tok/sMacBook Pro 16" M5 Max (128 GB)~33 tok/sMac Studio M4 Max (128 GB)~29 tok/sMac Studio M4 Max (64 GB)~29 tok/sMacBook Pro 16" M4 Max (48 GB)~29 tok/sMacBook Pro 16" M4 Max (64 GB)~29 tok/sMac Studio M4 Max (36 GB)~22 tok/sMacBook Pro 14" M4 Max (36 GB)~22 tok/sMacBook Pro 16" M3 Max (48 GB)~22 tok/sMacBook Pro 14-inch (M5 Pro)~17 tok/sMac Mini M4 Pro (24 GB)~15 tok/sMac Mini M4 Pro (48 GB)~15 tok/sMacBook Pro 14" M4 Pro (24 GB)~15 tok/sMacBook Pro 16" M4 Pro (24 GB)~15 tok/sASUS Ascent GX10~14 tok/sNVIDIA DGX Spark~14 tok/sNVIDIA Jetson AGX Thor Developer Kit~14 tok/sAsus ROG Flow Z13 (2025, Ryzen AI Max+ 395, 128 GB)~13 tok/sBeelink GTR9 Pro (Ryzen AI Max+ 395, 128 GB)~13 tok/sFramework Desktop (Ryzen AI Max+ 395, 128 GB)~13 tok/sGMKtec EVO-X2 (Ryzen AI Max+ 395, 128 GB)~13 tok/sHP Z2 Mini G1a (Ryzen AI Max+ PRO 395, 128 GB)~13 tok/sHP ZBook Ultra G1a 14 (Ryzen AI Max+ PRO 395, 128 GB)~13 tok/sMinisforum MS-S1 MAX (Ryzen AI Max+ 395, 128 GB)~13 tok/sSnapdragon X2 Elite Extreme Copilot+ PC~11 tok/sNVIDIA Jetson AGX Orin 32GB~10 tok/sNVIDIA Jetson AGX Orin 64GB~10 tok/sMacBook Pro 14-inch (M5)~8 tok/sSnapdragon X Elite Copilot+ PC~7 tok/sMac Mini M4 (32 GB)~7 tok/sMacBook Air 13" M4 (24 GB)~7 tok/sMacBook Air 15" M4 (24 GB)~7 tok/sMacBook Air 13" M3 (24 GB)~6 tok/sIntel Core Ultra 9 288V (Lunar Lake) Laptop~5 tok/sAMD Ryzen AI 9 HX 370 (Strix Point) Laptop~5 tok/s

Where to Download ERNIE 4.5 21B A3B PT

Community quantizations of this model — GGUF for llama.cpp, Ollama, and LM Studio, plus AWQ/MLX variants where available.

Related Models

Frequently Asked Questions

How much VRAM does ERNIE 4.5 21B A3B PT need?

ERNIE 4.5 21B A3B PT requires 13.0 GB of VRAM at Q4_K_M, or 42.4 GB at BF16. Full 131K context adds up to 7.4 GB (20.4 GB total).

VRAM = Weights + KV Cache + Overhead

Weights = 21B × 4.8 bits ÷ 8 = 12.6 GB

KV Cache + Overhead 0.4 GB (at 2K context + ~0.3 GB framework)

KV Cache + Overhead 7.8 GB (at full 131K context)

VRAM usage by quantization

13.0 GB
20.4 GB

Learn more about VRAM estimation →

Can NVIDIA GeForce RTX 4090 run ERNIE 4.5 21B A3B PT?

Yes, at Q8_0 (21.4 GB) or lower. Higher quantizations like BF16 (42.4 GB) exceed the NVIDIA GeForce RTX 4090's 24 GB.

What's the best quantization for ERNIE 4.5 21B A3B PT?

For ERNIE 4.5 21B A3B PT, Q4_K_M (13.0 GB) offers the best balance of quality and VRAM usage. Q4_K_L (13.3 GB) provides better quality if you have the VRAM. The smallest option is IQ2_XXS at 6.2 GB.

VRAM requirement by quantization

IQ2_XXS
6.2 GB
Q2_K
9.3 GB
IQ4_XS
11.7 GB
Q4_K_M
13.0 GB
Q4_K_L
13.3 GB
BF16
42.4 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run ERNIE 4.5 21B A3B PT on a Mac?

ERNIE 4.5 21B A3B PT requires at least 6.2 GB at IQ2_XXS, which exceeds the unified memory of most consumer Macs. You would need a Mac Studio or Mac Pro with a high-memory configuration.

Can I run ERNIE 4.5 21B A3B PT locally?

Yes — ERNIE 4.5 21B A3B PT can run locally on consumer hardware. At Q4_K_M quantization it needs 13.0 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is ERNIE 4.5 21B A3B PT?

At Q4_K_M, ERNIE 4.5 21B A3B PT can reach ~338 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~50 tok/s. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.

tok/s = (bandwidth GB/s ÷ model GB) × efficiency

Example: NVIDIA B2008000 ÷ 13.0 × 0.65 = ~399 tok/s

Estimated speed at Q4_K_M (13.0 GB)

~399 tok/s
~50 tok/s
~399 tok/s
~338 tok/s

Real-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.

Learn more about tok/s estimation →

What's the download size of ERNIE 4.5 21B A3B PT?

At Q4_K_M, the download is about 12.60 GB. The full-precision BF16 version is 42.00 GB. The smallest option (IQ2_XXS) is 5.78 GB.

Which GPUs can run ERNIE 4.5 21B A3B PT?

26 consumer GPUs can run ERNIE 4.5 21B A3B PT at Q4_K_M (13.0 GB). Top options include AMD Radeon RX 7900 XT, AMD Radeon RX 7900 XTX, NVIDIA GeForce RTX 3090, AMD Radeon RX 6800. 8 GPUs have plenty of headroom for comfortable inference.

Which devices can run ERNIE 4.5 21B A3B PT?

49 devices with unified memory can run ERNIE 4.5 21B A3B PT at Q4_K_M (13.0 GB), including AMD Ryzen AI 9 HX 370 (Strix Point) Laptop, ASUS Ascent GX10, Asus ROG Flow Z13 (2025, Ryzen AI Max+ 395, 128 GB), Beelink GTR9 Pro (Ryzen AI Max+ 395, 128 GB). Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.