Can gemma 3 27b it run on Mac Studio M3 Ultra 256GB?

Q: Is unified memory on Mac Studio M3 Ultra 256GB as fast as VRAM for gemma 3 27b it?

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.

YES — Runs Great

C44Usable

Estimated from fit model

gemma 3 27b it needs ~48.2 GB VRAM. Mac Studio M3 Ultra 256GB has 184.3 GB. With Q4_K_M quantization, expect ~34 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) — 48.2 GB, 33.8 tok/s, Runs well

48.2 GB required184.3 GB available

26% VRAM used

Fit status

Runs well

Decode

33.8 tok/s

TTFT

5725 ms

Safe context

704K

Memory

48.2 GB / 184.3 GB

Memory breakdown

Weights16.5 GB

KV Cache3.2 GB

Runtime0.9 GB

Headroom27.6 GB

See how fast it feels

See how fast it feelsgemma 3 27b it on Mac Studio M3 Ultra 256GB
1st promptCold start — includes initialization
>What is local AI inference?
Local AI inference means running an AI language model directly on your own hardware — your laptop, desktop, or server — instead of sending requests to a remote cloud API.

When you run inference locally the model weights are loaded into your GPU or unified memory. Each token you generate requires reading those weights from memory, so memory bandwidth is the main bottleneck for decode speed.

Key benefits of running locally:
  - Full privacy: your prompts never leave your machine
  - No per-token cost or rate limits
  - Works offline once the model is downloaded
  - Latency depends only on your hardware
2nd promptWarm — model ready, no init overhead
>How much VRAM do I need?
It depends on the model size and quantization level. A rough rule of thumb:

  Model size     Q4 (4-bit)    Q8 (8-bit)    FP16
  7B params      ~4.3 GB       ~7.5 GB       ~14 GB
  13B params     ~7.9 GB       ~13.9 GB      ~26 GB
  70B params     ~42.7 GB      ~74.9 GB      ~140 GB

Most people use 4-bit quantization (Q4_K_M) which gives 90-95% of full quality at a fraction of the memory. A 24 GB GPU can comfortably run most 7B-13B models.
Estimated: 33.8 tok/s decode · 5.7s TTFT (warm) · 85 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	C	Runs well	33.8 tok/s	3123 ms	704K
Coding	C	Runs well	33.8 tok/s	5725 ms	704K
Agentic Coding	C	Runs well	33.8 tok/s	8328 ms	704K
Reasoning	C	Runs well	33.8 tok/s	6766 ms	704K
RAG	C	Runs well	33.8 tok/s	10410 ms	704K

Quantization options

How gemma 3 27b it (27B params) fits at each quantization level on Mac Studio M3 Ultra 256GB (184.3 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	10.5 GB	Low	D37
Q3_K_S	3	13.2 GB	Low	D37
NVFP4	4

Get started

Copy-paste commands to run gemma 3 27b it on your machine.

Run

lms load hf-unsloth--gemma-3-27b-it-gguf && lms server start

Upgrade options

Hardware that runs gemma 3 27b it well

AMD Instinct MI350X 288GBBudget pick

288 GB VRAM (+32)8000 GB/s (+7181)

Raises estimated decode speed by about 949%.354.6 tok/s decode

Raises estimated decode speed by about 949%.

Adds memory headroom for longer context windows and future model growth.

~$8,000 MSRP

AMD Instinct MI300X 192GBBest value

5300 GB/s (+4481)

Raises estimated decode speed by about 643%.251 tok/s decode

Raises estimated decode speed by about 643%.

~$15,000 MSRP

Frequently asked questions

Can Mac Studio M3 Ultra 256GB run gemma 3 27b it?

Yes, Mac Studio M3 Ultra 256GB can run gemma 3 27b it with a C grade (Runs well). Expected decode speed: 33.8 tok/s.

How much VRAM does gemma 3 27b it need?

gemma 3 27b it (27B parameters) requires approximately 48.2 GB of memory with Q4_K_M quantization.

What is the best quantization for gemma 3 27b it?

The recommended quantization for gemma 3 27b it is Q4_K_M, which balances quality and memory efficiency.

What speed will gemma 3 27b it run at on Mac Studio M3 Ultra 256GB?

On Mac Studio M3 Ultra 256GB, gemma 3 27b it achieves approximately 33.8 tokens per second decode speed with a time-to-first-token of 5725ms using Q4_K_M quantization.

Can Mac Studio M3 Ultra 256GB run gemma 3 27b it for coding?

For coding workloads, gemma 3 27b it on Mac Studio M3 Ultra 256GB receives a C grade with 33.8 tok/s and 704K context.

What context window can gemma 3 27b it use on Mac Studio M3 Ultra 256GB?

On Mac Studio M3 Ultra 256GB, gemma 3 27b it can safely use up to 704K tokens of context. The model's official context limit is —, but available memory constrains the safe maximum.

Is unified memory on Mac Studio M3 Ultra 256GB as fast as VRAM for gemma 3 27b it?

See all results for Mac Studio M3 Ultra 256GB See all hardware for gemma 3 27b it

Embed this result▼

Paste this snippet into any page to show a live fit card.

<iframe src="https://willitrunai.com/embed/hf-unsloth--gemma-3-27b-it-gguf-on-m3-ultra-256gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>

Preview: