llmrun
BigScienceBloomForCausalLM

Bloom 1b1 — Hardware Requirements & GPU Compatibility

Chat

Bloom 1b1 is a 1.1B-parameter open language model from BigScience. At Q4_K_M it needs about 0.70 GB of VRAM — see which GPUs and Macs can run it below.

1.1B params · densebigscience-bloom-rail-1.032.5K downloads67 likes
S

Runs great on a 24 GB GPU

Runs from8 GB Q4_K_M · 32KBest on24 GB Q4_K_M · ~936 tok/s · 32KMacs from8 GB Q4_K_M · ~102 tok/s

bigscience-bloom-rail-1.0

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run Bloom 1b1

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 bigscience/bloom-1b1 --max-model-len 16384

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 3060 12GB (9 GB headroom) · Q4_K_M

Generation speed
~334 tok/s
generation speed
Cost per 1M output tokens
$0.051
per 1M output tokens

How Much VRAM Does Bloom 1b1 Need?

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

QuantizationVRAM+32KOn RTX 4090 (reference)
0.5 GB3.6 GB2-bit · K-quant — 2-bit quantization with K-quant improvementsFits: 32K context · ~1310 tok/s
0.6 GB3.7 GB3-bit medium — 3-bit medium quantizationFits: 32K context · ~1150 tok/s
0.7 GB3.8 GB4-bit medium — 4-bit medium quantization — most popular sweet spotFits: 32K context · ~936 tok/s
0.8 GB4 GB5-bit medium — 5-bit medium quantization — good quality/size tradeoffFits: 32K context · ~789 tok/s
1.0 GB4.1 GB6-bit, very good — 6-bit quantization, very good qualityFits: 32K context · ~676 tok/s
1.2 GB4.3 GB8-bit, near-lossless — 8-bit quantization, near-losslessFits: 32K context · ~560 tok/s
2.3 GB5.5 GB16-bit · bfloat — Brain floating point 16 — preferred for trainingFits: 32K context · ~280 tok/s
est.calculated, no published file yet

Selected Q4_K_M

4-bit medium quantization

2.2GBat 16K context

Weights
0.2 GB
KV cache
1.7 GB
Overhead
0.3 GB

Fits RTX 4090 (reference) · 21.8 GB free · ~936 tok/s

≥50 tok/s needs ≥54 GB/s · RTX 5090 ~1664, RTX 3090 Ti ~936

Which Hardware Can Run Bloom 1b1?

Q4_K_M · 0.7 GB

Bloom 1b1 (Q4_K_M) requires 0.7 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 Bloom 1b1, 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 · 2.2 GB · ~253 tok/s · 32K8 GB tier →
12 GB · RTX 3060 12GBQ4_K_M · 2.2 GB · ~334 tok/s · 32K12 GB tier →
16 GB · RTX 5060 Ti 16GBQ4_K_M · 2.2 GB · ~416 tok/s · 32K16 GB tier →
24 GB · RTX 4090referenceQ4_K_M · 2.2 GB · ~936 tok/s · 32K24 GB tier →
Mac 32 GB · Mac Mini M4Q4_K_M · 2.2 GB · ~120 tok/s · 32KMacs →
Mac 64 GB · Mac Studio M4 MaxQ4_K_M · 2.2 GB · ~546 tok/s · 32KMacs →

Alternatives to Bloom 1b1

Similar models

6
ModelScoreVRAMtok/sWhy it is similar
MiniCPM5 1BOpenBMB—1.3 GB~662same size
Gemma 3 1B ITGoogle—2.1 GB~993same size
TinyLlama 1.1B Chat v1.0TinyLlama—1 GB~649same size
LLaMA3.1 8B Instruct DFlash UltraChatz-lab—2.7 GB~269same size
Vaultgemma 1BGoogle—3.7 GB~286same size
TinyDolphin 2.8 1.1BQuixiAI—1.1 GB~649same size

Specifications

Publisher
BigScience
Parameters
1.1B
Architecture
BloomForCausalLM
Vocabulary Size
250,880
Release Date
2022-05-19
License
bigscience-bloom-rail-1.0

Frequently Asked Questions

How much VRAM does Bloom 1b1 need?

Bloom 1b1 requires 0.7 GB of VRAM at Q4_K_M, or 2.3 GB at BF16.

VRAM = Weights + KV Cache + Overhead

Weights = 1.1B × 4.8 bits ÷ 8 = 0.6 GB

KV Cache + Overhead ≈ 0.1 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

0.7 GB

Learn more about VRAM estimation →

What's the best quantization for Bloom 1b1?

For Bloom 1b1, Q4_K_M (0.7 GB) offers the best balance of quality and VRAM usage. Q5_K_M (0.8 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 0.5 GB.

VRAM requirement by quantization

Q2_K
0.5 GB
Q4_K_M ★
0.7 GB
Q5_K_M
0.8 GB
Q6_K
1.0 GB
Q8_0
1.2 GB
BF16
2.3 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run Bloom 1b1 on a Mac?

Yes — MacBook Air 13" M3 (8 GB) and 145 other Macs can run Bloom 1b1. Apple Silicon uses unified memory, so the model shares RAM with the system. At Q4_K_M you need at least 0.7 GB of usable unified memory (RAM minus macOS overhead).

Can I run Bloom 1b1 locally?

Yes — Bloom 1b1 can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is Bloom 1b1?

At Q4_K_M, Bloom 1b1 can reach ~6857 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~936 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 ÷ 0.7 × 0.65 = ~7429 tok/s

Estimated speed at Q4_K_M (0.7 GB)

~7429 tok/s
~936 tok/s
~7429 tok/s
~6857 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 Bloom 1b1?

At Q4_K_M, the download is about 0.64 GB. The full-precision BF16 version is 2.13 GB. The smallest option (Q2_K) is 0.45 GB.

Which GPUs can run Bloom 1b1?

52 consumer GPUs can run Bloom 1b1 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 Bloom 1b1?

163 devices with unified memory can run Bloom 1b1 at Q4_K_M (0.7 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.