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EleutherAIGPTNeoXForCausalLM

Pythia 2.8B — Hardware Requirements & GPU Compatibility

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Pythia 2.8B is a 2.9B-parameter open language model from EleutherAI. It supports a context window of up to 2,048 tokens. At Q4_K_M it needs about 1.92 GB of VRAM — see which GPUs and Macs can run it below.

2.9B params · dense2K contextApache 2.039.9K downloads35 likes
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Runs great on a 24 GB GPU

Runs from8 GB Q4_K_M · 2KBest on24 GB Q4_K_M · ~341 tok/s · 2KMacs from8 GB Q4_K_M · ~37 tok/s

Apache 2.0

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run Pythia 2.8B

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/pythia-2.8b --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) (10 GB headroom) · Q4_K_M

Generation speed
~309 tok/s
generation speed
Cost per 1M output tokens
$0.11
per 1M output tokens

How Much VRAM Does Pythia 2.8B Need?

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

QuantizationVRAM+32KOn RTX 4090 (reference)
1.4 GB—2-bit · K-quant — 2-bit quantization with K-quant improvementsFits: 2K context · ~482 tok/s
1.6 GB—3-bit medium — 3-bit medium quantizationFits: 2K context · ~420 tok/s
1.9 GB—4-bit medium — 4-bit medium quantization — most popular sweet spotFits: 2K context · ~341 tok/s
2.3 GB—5-bit medium — 5-bit medium quantization — good quality/size tradeoffFits: 2K context · ~287 tok/s
2.6 GB—6-bit, very good — 6-bit quantization, very good qualityFits: 2K context · ~248 tok/s
3.2 GB—8-bit, near-lossless — 8-bit quantization, near-losslessFits: 2K context · ~205 tok/s
6.4 GB—16-bit · full — Full half-precision — baseline for inferenceFits: 2K context · ~102 tok/s
est.calculated, no published file yet

Selected Q4_K_M

4-bit medium quantization

1.9GBat 2K context

Weights
1.3 GB
KV cache
0.3 GB
Overhead
0.3 GB

Fits RTX 4090 (reference) · 22.1 GB free · ~341 tok/s

≥50 tok/s needs ≥148 GB/s · RTX 5090 ~607, RTX 3090 Ti ~341

Which Hardware Can Run Pythia 2.8B?

Q4_K_M · 1.9 GB

Pythia 2.8B (Q4_K_M) requires 1.9 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 3+ 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 Pythia 2.8B, including Mac Studio (M3 Ultra, 256GB), Mac Studio (M3 Ultra, 512GB).

By VRAM tier · typical GPUs and Macs at Q4_K_M
8 GB · RTX 4060Q4_K_M · 1.9 GB · ~92 tok/s · 2K8 GB tier →
12 GB · RTX 3060 12GBQ4_K_M · 1.9 GB · ~122 tok/s · 2K12 GB tier →
16 GB · RTX 5060 Ti 16GBQ4_K_M · 1.9 GB · ~152 tok/s · 2K16 GB tier →
24 GB · RTX 4090referenceQ4_K_M · 1.9 GB · ~341 tok/s · 2K24 GB tier →
Mac 32 GB · Mac Mini M4Q4_K_M · 1.9 GB · ~44 tok/s · 2KMacs →
Mac 64 GB · Mac Studio M4 MaxQ4_K_M · 1.9 GB · ~199 tok/s · 2KMacs →

Alternatives to Pythia 2.8B

Similar models

6
ModelScoreVRAMtok/sWhy it is similar
LFM2.5 2.6BLiquid AI—2.3 GB~321same size
SmolLM3 3BHugging Face—3.4 GB~285same size
Phi 2Microsoft—2.6 GB~248same size
Nemotron Flash 3BNVIDIA—7.6 GB~109same size
Qwen2.5 3B InstructAlibaba—2.8 GB~294same size
Stablelm 3B 4e1tStability AI—3.3 GB~247same size

Specifications

Publisher
EleutherAI
Parameters
2.9B
Architecture
GPTNeoXForCausalLM
Context Length
2,048 tokens
Vocabulary Size
50,304
Release Date
2023-02-13
License
Apache 2.0

Frequently Asked Questions

How much VRAM does Pythia 2.8B need?

Pythia 2.8B requires 1.9 GB of VRAM at Q4_K_M, or 6.4 GB at FP16.

VRAM = Weights + KV Cache + Overhead

Weights = 2.9B × 4.8 bits ÷ 8 = 1.7 GB

KV Cache + Overhead ≈ 0.2 GB (at 2K context + ~0.3 GB framework)

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

1.9 GB

Learn more about VRAM estimation →

What's the best quantization for Pythia 2.8B?

For Pythia 2.8B, Q4_K_M (1.9 GB) offers the best balance of quality and VRAM usage. Q5_K_M (2.3 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 1.4 GB.

VRAM requirement by quantization

Q2_K
1.4 GB
Q4_K_M ★
1.9 GB
Q5_K_M
2.3 GB
Q6_K
2.6 GB
Q8_0
3.2 GB
FP16
6.4 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run Pythia 2.8B on a Mac?

Yes — Mac Mini M2 (8 GB) and 145 other Macs can run Pythia 2.8B. Apple Silicon uses unified memory, so the model shares RAM with the system. At Q4_K_M you need at least 1.9 GB of usable unified memory (RAM minus macOS overhead).

Can I run Pythia 2.8B locally?

Yes — Pythia 2.8B can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is Pythia 2.8B?

At Q4_K_M, Pythia 2.8B can reach ~2500 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~341 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 ÷ 1.92 × 0.65 = ~2708 tok/s

Estimated speed at Q4_K_M (1.9 GB)

~2708 tok/s
~341 tok/s
~2708 tok/s
~2500 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 Pythia 2.8B?

At Q4_K_M, the download is about 1.75 GB. The full-precision FP16 version is 5.82 GB. The smallest option (Q2_K) is 1.24 GB.

Which GPUs can run Pythia 2.8B?

52 consumer GPUs can run Pythia 2.8B at Q4_K_M. 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 Pythia 2.8B?

163 devices with unified memory can run Pythia 2.8B at Q4_K_M (1.9 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.