Family ERNIE · 21B parameters

ERNIE 4.5 21B-A3B Thinking

Compact MoE reasoner, 21B/3B active. Apache 2.0. Fast thanks to 3B active.

🇨🇳 Baidu·License Apache 2.0·Context 128k tokens·Output April 2025·Fits within the 128 GB of the GIGABYTE AI TOP ATOM← Catalog

01What it can do

Strengths
  • 13 GB VRAM Q4
  • Compact MoE reasoning
  • Strong in Chinese
Limitations to know
  • —Less multilingual than Qwen
  • —Baidu license to verify
Architecture
MoE · 21B · compact ERNIE 4.5 · optimized reasoning
Training
Compact version of Baidu ERNIE 4.5 with reasoning specialization.
Ideal for
Laptop reasoningMath

04Install

Install Ollama for your OS. Check the model and its quantization before downloading. Start with 4096 tokens of context, then check placement with ollama ps. A command below is not proof that a test was run on your machine.

$ollama pull hf.co/baidu/ernie-4.5-21b-GGUF
⚠
First download: between 2 and 40 GB depending on the selected quantization. Plan for sufficient disk space; a stable connection is recommended. Subsequent launches are instant.

02Required memory

Approximate GPU VRAM required to run this model, including 4k tokens of context overhead. For a longer context, add ~1 GB per 8k-token increment.

Q4_K_M
The lightest, ~5% loss
13 GB
Q5_K_M
Good quality/size compromise
16 GB
Q8_0
Nearly indistinguishable from FP16
23 GB
FP16
Full precision — server use
42 GB
Fallback CPU · If you don't have a GPU, allow 18 GB of RAM minimum to run this model at reduced speed.

What hardware do you need for ERNIE 4.5 21B-A3B Thinking?

To run ERNIE 4.5 21B-A3B Thinking locally with Q4 quantization, you need about 13 GB of VRAM. An option to compare: GMKtec EVO-X2 64GB / 1TB (Ryzen AI Max+ 395) — leave some headroom for the system and context; check engine compatibility with the GPU.

Current offer: GMKtec EVO-X2 64GB / 1TB (Ryzen AI Max+ 395)
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Why this choice? Our complete guide on GMKtec EVO-X2 64GB / 1TB (Ryzen AI Max+ 395) →

Affiliate links — commission possible at no extra cost to you; independent recommendation. As an Amazon Associate, BestLLMfor earns from qualifying purchases.

On the go: ERNIE 4.5 21B-A3B Thinking also runs on a RTX laptop PC (16 GB of VRAM) →

This model in your private ChatGPT, without the cloud

Your private ChatGPT, free, on your own machine in an hour — LM Studio, Ollama, Open WebUI, your documents, no cloud.

  • Lifetime online access
  • PDF + files
  • Lifetime updates

03Expected speed

Tokens generated per second in Q4_K_M, 4k context. Beyond 20 t/s, reading is comfortable. Below 10 t/s, that's just for testing.

Entry-level
~15t/s
GTX 1650, RX 6600, MBA M2 8GB
Mid-range
~40t/s
RTX 4060, 4070, MBP M3 Pro
High-end
~100t/s
RTX 4090, M4 Max, Radeon 7900