Is unified memory on MacBook Air M4 24GB as fast as VRAM for Devstral Small 2 24B Instruct?

Not always. MacBook Air M4 24GB 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.

Can Devstral Small 2 24B Instruct run on MacBook Air M4 24GB?

Q: What should I upgrade first if Devstral Small 2 24B Instruct feels slow on MacBook Air M4 24GB?

Remove offload with more accelerator memory. Prioritize a GPU or unified-memory tier that fits the whole model natively. Removing offload usually helps more than small compute gains.

BARELY — Tight on Memory

B70Good

Estimated — low-sample bucket· few comparable runs

Devstral Small 2 24B Instruct needs ~20.6 GB VRAM. MacBook Air M4 24GB has 17.3 GB. With Q4_K_M quantization, expect ~5 tok/s.

Runtime: llama.cppCapacity: OffloadBandwidth: Very lowStack: StandardBottleneck: Host offload

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) — 20.6 GB, 7.3 tok/s, Very compromised (needs ~2.3 GB host RAM)

20.6 GB required17.3 GB available

119% VRAM needed

3.3 GB over capacity — needs offload or smaller quantization

Fit status

Very compromised (needs ~2.3 GB host RAM)

Decode

7.3 tok/s

TTFT

26452 ms

Safe context

Memory

20.6 GB / 17.3 GB

Offload

20%

Memory breakdown

Weights14.6 GB

KV Cache2.4 GB

Runtime0.9 GB

Headroom2.6 GB

See how fast it feels

See how fast it feelsDevstral Small 2 24B Instruct on MacBook Air M4 24GB
1st promptCold start — includes initialization
>Write a Python function to sort a list
Here's a Python function that sorts a list using quicksort:

def quicksort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left   = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right  = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

# Example usage
numbers = [3, 6, 8, 10, 1, 2, 1]
print(quicksort(numbers))  # [1, 1, 2, 3, 6, 8, 10]

The algorithm picks a pivot, partitions the list into smaller, equal, and larger elements, then recursively sorts each partition and concatenates the results.
2nd promptWarm — model ready, no init overhead
>Now add type hints and a docstring
def quicksort(arr: list[int]) -> list[int]:
    """Sort a list using the quicksort algorithm.

    Args:
        arr: List of integers to sort.

    Returns:
        A new sorted list.
    """
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left   = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right  = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

Added type hints for the input and return type, plus a Google-style docstring.
Estimated: 7.3 tok/s decode · 26.5s TTFT (warm) · 18 tok/s prefill

What limits this setup

It fits through host-memory offload, and offload is the main reason performance drops.

CPU or host-memory offload is active

About 20% of the working set spills out of accelerator memory, which usually hurts latency and sustained decode throughput.

Very little memory headroom

You can run the model, but there is not much room left for longer context, bigger batches, extra apps, or future model updates.

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

Remove offload with more accelerator memory

Prioritize a GPU or unified-memory tier that fits the whole model natively. Removing offload usually helps more than small compute gains.

Buy headroom, not only minimum fit

A slightly larger memory tier gives you safer context growth and makes the recommendation more future-proof.

Increase host RAM if you keep offloading

This setup may need roughly {ram} GB of extra host RAM just for the offloaded portion, before OS and other tools.

Performance by workload

Workload	Grade	Fit	Decode	TTFT	Context
Chat	A	Very compromised (needs ~1.6 GB host RAM)	7.9 tok/s	13328 ms	4K
Coding	B	Very compromised	4.5 tok/s	42654 ms	4K
Agentic Coding	F	Too heavy	6.4 tok/s	44101 ms	4K
Reasoning	A	Very compromised (needs ~2.3 GB host RAM)	7.3 tok/s	31262 ms	4K
RAG	F	Too heavy	6.4 tok/s	55126 ms

Quantization options

How Devstral Small 2 24B Instruct (24B params) fits at each quantization level on MacBook Air M4 24GB (17.3 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	9.4 GB	Low	S92
Q3_K_SBest for your GPU	3	11.8 GB	Low	S92

Get started

Copy-paste commands to run Devstral Small 2 24B Instruct on your machine.

Run

ollama run devstral-small-2

Upgrade options

Hardware that runs Devstral Small 2 24B Instruct well

MacBook Pro M4 32GBBudget pick

32 GB Unified (+8)

Removes host-memory offload, which is usually the single biggest latency and throughput win.9.5 tok/s decode

Removes host-memory offload, which is usually the single biggest latency and throughput win.

Raises estimated decode speed by about 30%.

~$799 MSRP

Mac mini M4 32GBBest value

32 GB Unified (+8)

Removes host-memory offload, which is usually the single biggest latency and throughput win.9.5 tok/s decode

Removes host-memory offload, which is usually the single biggest latency and throughput win.

Raises estimated decode speed by about 30%.

~$1,099 MSRP

Mac mini M4 64GBApple upgrade

64 GB Unified (+40)

Removes host-memory offload, which is usually the single biggest latency and throughput win.9.5 tok/s decode

Removes host-memory offload, which is usually the single biggest latency and throughput win.

Raises estimated decode speed by about 30%.

~$1,099 MSRP

RTX 5090 32GBBiggest leap

32 GB VRAM (+8)1792 GB/s (+1672)

Removes host-memory offload, which is usually the single biggest latency and throughput win.62 tok/s decode

Removes host-memory offload, which is usually the single biggest latency and throughput win.

Raises estimated decode speed by about 749%.

~$1,999 MSRP

Frequently asked questions

Can MacBook Air M4 24GB run Devstral Small 2 24B Instruct?

Yes, MacBook Air M4 24GB can run Devstral Small 2 24B Instruct with a B grade (Very compromised). Expected decode speed: 4.5 tok/s.

How much VRAM does Devstral Small 2 24B Instruct need?

Devstral Small 2 24B Instruct (24B parameters) requires approximately 20.6 GB of memory with Q4_K_M quantization.

What is the best quantization for Devstral Small 2 24B Instruct?

The recommended quantization for Devstral Small 2 24B Instruct is Q4_K_M, which balances quality and memory efficiency.

What speed will Devstral Small 2 24B Instruct run at on MacBook Air M4 24GB?

On MacBook Air M4 24GB, Devstral Small 2 24B Instruct achieves approximately 4.5 tokens per second decode speed with a time-to-first-token of 42654ms using Q4_K_M quantization.

Can MacBook Air M4 24GB run Devstral Small 2 24B Instruct for coding?

For coding workloads, Devstral Small 2 24B Instruct on MacBook Air M4 24GB receives a B grade with 4.5 tok/s and 4K context.

What context window can Devstral Small 2 24B Instruct use on MacBook Air M4 24GB?

On MacBook Air M4 24GB, Devstral Small 2 24B Instruct can safely use up to 4K tokens of context. The model's official context limit is 256K, but available memory constrains the safe maximum.

See all results for MacBook Air M4 24GB See all hardware for Devstral Small 2 24B Instruct

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