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MicrosoftPhi 3Phi3ForCausalLM

Phi 3 Medium 4k Instruct — Hardware Requirements & GPU Compatibility

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Phi 3 Medium 4k Instruct is a 14.0B-parameter open language model from Microsoft in the Phi 3 family. It supports a context window of up to 4,096 tokens. At Q4_K_M it needs about 9.10 GB of VRAM — see which GPUs and Macs can run it below.

14.0B params · dense4K contextMIT11.3K downloads225 likes
S

Runs great on a 24 GB GPU

Runs from8 GB Q3_K_M · 4KBest on24 GB Q4_K_M · ~72 tok/s · 4KMacs from16 GB Q4_K_M · ~15 tok/s

MIT

Reference GPU · RTX 4090 24 GB

Estimates, ±20% · how we estimate

Run Phi 3 Medium 4k Instruct

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 microsoft/Phi-3-medium-4k-instruct --max-model-len 4096

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) (2 GB headroom) · Q4_K_M

Generation speed
~65 tok/s
generation speed
Cost per 1M output tokens
$0.52
per 1M output tokens

How Much VRAM Does Phi 3 Medium 4k Instruct Need?

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

QuantizationVRAM+32KOn RTX 4090 (reference)
6.7 GB—2-bit · K-quant — 2-bit quantization with K-quant improvementsFits: 4K context · ~99 tok/s
7.5 GB—3-bit medium — 3-bit medium quantizationFits: 4K context · ~87 tok/s
9.1 GB—4-bit medium — 4-bit medium quantization — most popular sweet spotFits: 4K context · ~72 tok/s
10.7 GB—5-bit medium — 5-bit medium quantization — good quality/size tradeoffFits: 4K context · ~61 tok/s
12.2 GB—6-bit, very good — 6-bit quantization, very good qualityFits: 4K context · ~54 tok/s
14.7 GB—8-bit, near-lossless — 8-bit quantization, near-losslessFits: 4K context · ~45 tok/s
28.6 GB—16-bit · bfloat — Brain floating point 16 — preferred for trainingDoes not fit: needs 28.6 GB
est.calculated, no published file yet

Selected Q4_K_M

4-bit medium quantization

9.5GBat 4K context

Weights
8.4 GB
KV cache
0.8 GB
Overhead
0.3 GB

Fits RTX 4090 (reference) · 14.5 GB free · ~72 tok/s

≥50 tok/s needs ≥699 GB/s · RTX 5090 ~128, RTX 3090 Ti ~72

Which Hardware Can Run Phi 3 Medium 4k Instruct?

Q4_K_M · 9.1 GB

Phi 3 Medium 4k Instruct (Q4_K_M) requires 9.1 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 12+ GB is recommended. Using the full 4K context window can add up to 0.4 GB, bringing total usage to 9.5 GB. 40 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti, NVIDIA GeForce RTX 3080 Ti. 150 devices with unified memory can run Phi 3 Medium 4k Instruct, including Mac Studio (M3 Ultra, 256GB), Mac Studio (M3 Ultra, 512GB), Mac Mini M2 Pro (16 GB).

By VRAM tier · typical GPUs and Macs at Q4_K_M
8 GB · RTX 4060Q3_K_M · 8 GB · ~24 tok/s · 4K8 GB tier →
12 GB · RTX 3060 12GBQ4_K_M · 9.5 GB · ~26 tok/s · 4K12 GB tier →
16 GB · RTX 5060 Ti 16GBQ4_K_M · 9.5 GB · ~32 tok/s · 4K16 GB tier →
24 GB · RTX 4090referenceQ4_K_M · 9.5 GB · ~72 tok/s · 4K24 GB tier →
Mac 32 GB · Mac Mini M4Q4_K_M · 9.5 GB · ~9 tok/s · 4KMacs →
Mac 64 GB · Mac Studio M4 MaxQ4_K_M · 9.5 GB · ~42 tok/s · 4KMacs →

How good is Phi 3 Medium 4k Instruct?

llmrun Score blends public benchmark boards into one number; 100 = the average open model.

Not enough data yet for an llmrun Score.

A Score needs results on enough independent boards. How the Composite Score is built

Benchmarks

Here are all 2 boards that have results for this model, sorted by their weight in the llmrun Score; badges show who ran the test.

  • LMArena Text

    LMArena · Oct 2026Arena

    1198.0

    #147/188 open

    Arena
  • MMLU-Pro

    TIGER-LabIndependent

    55.7%

    #65/146 open

    Independent

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Specifications

Publisher
Microsoft
Family
Phi 3
Parameters
14.0B
Architecture
Phi3ForCausalLM
Context Length
4,096 tokens
Vocabulary Size
32,064
Release Date
2024-05-07
License
MIT

Frequently Asked Questions

How much VRAM does Phi 3 Medium 4k Instruct need?

Phi 3 Medium 4k Instruct requires 9.1 GB of VRAM at Q4_K_M, or 28.6 GB at BF16.

VRAM = Weights + KV Cache + Overhead

Weights = 14.0B × 4.8 bits ÷ 8 = 8.4 GB

KV Cache + Overhead ≈ 0.7 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.

KV Cache + Overhead ≈ 1.1 GB (at full 4K context)

VRAM usage by quantization

9.1 GB
9.5 GB

Learn more about VRAM estimation →

Can NVIDIA GeForce RTX 4090 run Phi 3 Medium 4k Instruct?

Yes, at Q8_0 (14.7 GB) or lower. Higher quantizations like BF16 (28.6 GB) exceed the NVIDIA GeForce RTX 4090's 24 GB.

What's the best quantization for Phi 3 Medium 4k Instruct?

For Phi 3 Medium 4k Instruct, Q4_K_M (9.1 GB) offers the best balance of quality and VRAM usage. Q5_K_M (10.7 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 6.7 GB.

VRAM requirement by quantization

Q2_K
6.7 GB
Q4_K_M ★
9.1 GB
Q5_K_M
10.7 GB
Q6_K
12.2 GB
Q8_0
14.7 GB
BF16
28.6 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run Phi 3 Medium 4k Instruct on a Mac?

Yes — Mac Mini M2 Pro (16 GB) and 133 other Macs can run Phi 3 Medium 4k Instruct. Apple Silicon uses unified memory, so the model shares RAM with the system. At Q4_K_M you need at least 9.1 GB of usable unified memory (RAM minus macOS overhead).

Can I run Phi 3 Medium 4k Instruct locally?

Yes — Phi 3 Medium 4k Instruct can run locally on consumer hardware. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is Phi 3 Medium 4k Instruct?

At Q4_K_M, Phi 3 Medium 4k Instruct can reach ~528 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~72 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 ÷ 9.1 × 0.65 = ~571 tok/s

Estimated speed at Q4_K_M (9.1 GB)

~571 tok/s
~72 tok/s
~571 tok/s
~528 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 Phi 3 Medium 4k Instruct?

At Q4_K_M, the download is about 8.38 GB. The full-precision BF16 version is 27.92 GB. The smallest option (Q2_K) is 5.93 GB.

Which GPUs can run Phi 3 Medium 4k Instruct?

40 consumer GPUs can run Phi 3 Medium 4k Instruct at Q4_K_M. Top options include AMD Radeon RX 6800, AMD Radeon RX 6800 XT, AMD Radeon RX 6900 XT, AMD Radeon RX 6700 XT. 26 GPUs have plenty of headroom for comfortable inference.

Which devices can run Phi 3 Medium 4k Instruct?

150 devices with unified memory can run Phi 3 Medium 4k Instruct at Q4_K_M (9.1 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.