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EleutherAIGPTNeoForCausalLM

GPT Neo 125M — Hardware Requirements & GPU Compatibility

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GPT Neo 125M is a 150M-parameter open language model from EleutherAI. It supports a context window of up to 2,048 tokens. At BF16 it needs about 0.33 GB of VRAM — see which GPUs and Macs can run it below.

150M params · dense2K contextMIT464.8K downloads231 likes
S

Runs great on a 24 GB GPU

Runs from8 GB BF16 · 2KBest on24 GB BF16 · ~1986 tok/s · 2KMacs from8 GB BF16 · ~217 tok/s

MIT

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run GPT Neo 125M

One recommended way. Every other method, OS and quant is in the step-by-step guide.Each way opens a step-by-step guide for your OS and quant.

Recommended

vLLM
one command · needs vLLM installed
$vllm serve EleutherAI/gpt-neo-125m --max-model-len 2048

vLLM repo with its own quantisation

Download: Weights on Hugging Face

install, OS, other quants

Ways to runOther ways

each opens step-by-step

Run in cloud

Runs on RTX 3080 Ti (12 GB) (11 GB headroom) · BF16

Generation speed
~1797 tok/s
generation speed
Cost per 1M output tokens
$0.019
per 1M output tokens

How Much VRAM Does GPT Neo 125M Need?

Select a quantization level; the listed hardware adheres to it.

QuantizationVRAM+32KOn RTX 4090 (reference)
0.3 GB—16-bit · bfloat — Brain floating point 16 — preferred for trainingFits: 2K context · ~1986 tok/s
est.calculated, no published file yet

Selected BF16

Brain floating point 16

0.3GBat 2K context

Weights
0.1 GB
KV cache
0.0 GB
Overhead
0.3 GB

Fits RTX 4090 (reference) · 23.7 GB free · ~1986 tok/s

≥50 tok/s needs ≥25 GB/s · RTX 5090 ~3530, RTX 3090 Ti ~1986

Which Hardware Can Run GPT Neo 125M?

BF16 · 0.3 GB

GPT Neo 125M (BF16) requires 0.3 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 1+ GB is recommended. 52 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti. 163 devices with unified memory can run GPT Neo 125M, including Mac Studio (M3 Ultra, 256GB), Mac Studio (M3 Ultra, 512GB).

By VRAM tier · typical GPUs and Macs at BF16
8 GB · RTX 4060BF16 · 0.3 GB · ~536 tok/s · 2K8 GB tier →
12 GB · RTX 3060 12GBBF16 · 0.3 GB · ~709 tok/s · 2K12 GB tier →
16 GB · RTX 5060 Ti 16GBBF16 · 0.3 GB · ~882 tok/s · 2K16 GB tier →
24 GB · RTX 4090referenceBF16 · 0.3 GB · ~1986 tok/s · 2K24 GB tier →
Mac 32 GB · Mac Mini M4BF16 · 0.3 GB · ~255 tok/s · 2KMacs →
Mac 64 GB · Mac Studio M4 MaxBF16 · 0.3 GB · ~1158 tok/s · 2KMacs →

Specifications

Publisher
EleutherAI
Parameters
150M
Architecture
GPTNeoForCausalLM
Context Length
2,048 tokens
Vocabulary Size
50,257
Release Date
2022-03-02
License
MIT

Frequently Asked Questions

How much VRAM does GPT Neo 125M need?

GPT Neo 125M requires 0.3 GB of VRAM at BF16.

VRAM = Weights + KV Cache + Overhead

Weights = 150M × 16 bits ÷ 8 = 0.3 GB

Fit ratings and hardware model lists check this model with room for a 16K-token context, which needs a little more memory.

VRAM usage by quantization

0.3 GB

Learn more about VRAM estimation →

Can I run GPT Neo 125M on a Mac?

Yes — MacBook Air 13" M3 (8 GB) and 145 other Macs can run GPT Neo 125M. Apple Silicon uses unified memory, so the model shares RAM with the system. At BF16 you need at least 0.3 GB of usable unified memory (RAM minus macOS overhead).

Can I run GPT Neo 125M locally?

Yes — GPT Neo 125M can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is GPT Neo 125M?

At BF16, GPT Neo 125M can reach ~14546 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~1986 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 B200 → 8000 ÷ 0.33 × 0.65 = ~15758 tok/s

Estimated speed at BF16 (0.3 GB)

~15758 tok/s
~1986 tok/s
~15758 tok/s
~14546 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 GPT Neo 125M?

At BF16, the download is about 0.30 GB.

Which GPUs can run GPT Neo 125M?

52 consumer GPUs can run GPT Neo 125M at BF16. Top options include AMD Radeon RX 6700 XT, AMD Radeon RX 6800, AMD Radeon RX 6800 XT. 52 GPUs have plenty of headroom for comfortable inference.

Which devices can run GPT Neo 125M?

163 devices with unified memory can run GPT Neo 125M at BF16 (0.3 GB), including AMD Ryzen AI 9 HX 370 (Strix Point) Laptop, ASUS Ascent GX10, Beelink GTR9 Pro (Ryzen AI Max+ 395, 128 GB), Framework Desktop (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.