Can Command R+ 104B run on Mac Studio M3 Ultra 256GB?

YES — Runs Great

B63Good

○Estimated from fit model

Command R+ 104B needs ~95.4 GB VRAM. Mac Studio M3 Ultra 256GB has 184.3 GB. With Q4_K_M quantization, expect ~10 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) — 95.4 GB, 9.5 tok/s, Runs well

95.4 GB required184.3 GB available

52% VRAM used

Fit status

Runs well

Decode

9.5 tok/s

TTFT

20279 ms

Safe context

131K

Memory

95.4 GB / 184.3 GB

Memory breakdown

Weights63.4 GB

KV Cache3.4 GB

Runtime0.9 GB

Headroom27.6 GB

See how fast it feels

See how fast it feelsCommand R+ 104B 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: 9.5 tok/s decode · 20.3s TTFT (warm) · 24 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	9.5 tok/s	11061 ms	131K
Coding	B	Runs well	9.5 tok/s	20279 ms	131K
Agentic Coding	B	Runs well	9.5 tok/s	29497 ms	131K
Reasoning	B	Runs well	9.5 tok/s	23966 ms	131K
RAG	B	Runs well	9.5 tok/s	36871 ms	131K

Quantization options

How Command R+ 104B (104B params) fits at each quantization level on Mac Studio M3 Ultra 256GB (184.3 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	40.6 GB	Low	B58
Q3_K_S	3	51.0 GB	Low	B59
NVFP4	4	58.2 GB	Medium	B60
Q4_K_M	4	63.4 GB	Medium	B60
Q5_K_M	5	74.9 GB	High	B62
Q6_K	6	85.3 GB	High	B63
Q8_0Best for your GPU	8	111.3 GB	Very High	B65
F16	16	213.2 GB	Maximum	F0