Can WizardLM 13B run on Mac Studio M3 Ultra 256GB?

YES — Runs Great

B67Good

Estimated from fit model

WizardLM 13B needs ~48.7 GB VRAM. Mac Studio M3 Ultra 256GB has 184.3 GB. With Q4_K_M quantization, expect ~70 tok/s.

Runtime: llama.cppCapacity: RoomyBandwidth: HighStack: StandardBottleneck: Balanced

Operating mode

Choose the run profile you care about

Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.

Current mode

Balanced

Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.

Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) — 48.7 GB, 70.2 tok/s, Runs well

48.7 GB required184.3 GB available

26% VRAM used

Fit status

Runs well

Decode

70.2 tok/s

TTFT

2757 ms

Safe context

Memory

48.7 GB / 184.3 GB

Memory breakdown

Weights7.9 GB

KV Cache12.2 GB

Runtime0.9 GB

Headroom27.6 GB

See how fast it feels

See how fast it feelsWizardLM 13B on Mac Studio M3 Ultra 256GB
1st promptCold start — includes initialization
>Solve: If a train travels at 60 mph for 2.5 hours, how far does it go?
Let me work through this step by step.

Given information:
  - Speed = 60 mph (miles per hour)
  - Time  = 2.5 hours

Formula: Distance = Speed x Time

Calculation:
  Distance = 60 mph x 2.5 h
           = 150 miles

The train travels 150 miles.

Double-check: at 60 mph the train covers 60 miles each hour. In half an hour it covers 30 miles. So in 2.5 hours: 60 + 60 + 30 = 150 miles. Confirmed.
2nd promptWarm — model ready, no init overhead
>What if the train stops for 20 minutes halfway?
The stop doesn't change the total distance covered while moving, but it affects total trip time.

Breakdown:
  - First half: 1.25 hours at 60 mph = 75 miles
  - Stop: 20 minutes (no distance)
  - Second half: 1.25 hours at 60 mph = 75 miles

Total distance: 150 miles (same)
Total time: 2.5 h + 0.33 h = 2.83 hours
Average speed: 150 / 2.83 = 53 mph

The distance stays the same but average speed drops to 53 mph because of the stop.
Estimated: 70.2 tok/s decode · 2.8s TTFT (warm) · 176 tok/s prefill

What limits this setup

This setup is broadly balanced for this model.

Shared-memory contention still exists

The OS, browser, and inference runtime all compete for the same physical memory pool, so real-world headroom is less forgiving than raw capacity suggests.

Best improvement path

Performance by workload

Workload	Grade	Fit	Decode	TTFT	Context
Chat	B	Runs well	70.2 tok/s	1504 ms	8K
Coding	B	Runs well	70.2 tok/s	2757 ms	8K
Agentic Coding	B	Runs well	70.2 tok/s	4010 ms	8K
Reasoning	B	Runs well	70.2 tok/s	3258 ms	8K
RAG	B	Runs well	70.2 tok/s	5012 ms	8K

Quantization options

How WizardLM 13B (13B params) fits at each quantization level on Mac Studio M3 Ultra 256GB (184.3 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	5.1 GB	Low	B58
Q3_K_S	3	6.4 GB	Low	B58
NVFP4	4	7.3 GB	Medium	B58
Q4_K_M	4	7.9 GB	Medium	B58
Q5_K_M	5	9.4 GB	High	B58
Q6_K	6	10.7 GB	High	B58
Q8_0	8	13.9 GB	Very High	B58
F16Best for your GPU	16	26.7 GB	Maximum	B59

Get started

Copy-paste commands to run WizardLM 13B on your machine.

Run

lms load WizardLM-13B-V1.0 && lms server start

Frequently asked questions

Can Mac Studio M3 Ultra 256GB run WizardLM 13B?

Yes, Mac Studio M3 Ultra 256GB can run WizardLM 13B with a B grade (Runs well). Expected decode speed: 70.2 tok/s.

How much VRAM does WizardLM 13B need?

WizardLM 13B (13B parameters) requires approximately 48.7 GB of memory with Q4_K_M quantization.

What is the best quantization for WizardLM 13B?

The recommended quantization for WizardLM 13B is Q4_K_M, which balances quality and memory efficiency.

What speed will WizardLM 13B run at on Mac Studio M3 Ultra 256GB?

On Mac Studio M3 Ultra 256GB, WizardLM 13B achieves approximately 70.2 tokens per second decode speed with a time-to-first-token of 2757ms using Q4_K_M quantization.

Can Mac Studio M3 Ultra 256GB run WizardLM 13B for coding?

For coding workloads, WizardLM 13B on Mac Studio M3 Ultra 256GB receives a B grade with 70.2 tok/s and 8K context.

What context window can WizardLM 13B use on Mac Studio M3 Ultra 256GB?

On Mac Studio M3 Ultra 256GB, WizardLM 13B can safely use up to 8K tokens of context. The model's official context limit is 8K, but available memory constrains the safe maximum.

Is unified memory on Mac Studio M3 Ultra 256GB as fast as VRAM for WizardLM 13B?

Not always. Mac Studio M3 Ultra 256GB can often fit larger models thanks to unified memory, but a discrete GPU with dedicated high-bandwidth VRAM may still decode faster once the model fits. For this combination, the important distinction is capacity versus sustained throughput.

See all results for Mac Studio M3 Ultra 256GB See all hardware for WizardLM 13B

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