Sunk Cost sunkcost.ai Data checked 2026-09-03

What hardware do you need to run Devstral 2 123B?

Devstral 2 123B at Q4_K_M is 75 GB of weights, with a context ceiling of 256k tokens. Not yet rated: released after our last ratings pass. Dense 123B: every parameter is read for every token, so it is slow as well as large.

Cheapest machine that runs itStrix Halo Framework Desktop, 128GB at $3,449
Fastest of the ones listedMac Studio M5 Ultra, 256GB — 10 tok/s at 32k context
Honest answer on costPays back in 59 years at 500k tokens a day.

How good is it, really?

On the Artificial Analysis Intelligence Index v4.3 it scores 9, which puts it in the Below every hosted tier band. Fine for simple, well-specified tasks. Noticeably less capable than anything the big labs sell today. Score source. See the whole table.

What it costs either way

Renting the same model costs $0.4 per million input tokens and $2 per million output (OpenRouter, cheapest active endpoint, checked 2026-09-15). Buying a machine only beats that if you use it hard enough, for long enough, that the hardware price divides down below the rental bill.

Machines that run it

MachinePriceSpeed at 32kPay-back
Strix Halo Framework Desktop, 128GB $3,449 2.2 tok/s estimated Pays back in 59 years Run the numbers
DGX Spark GB10 Grace Blackwell, 128GB $4,699 2.4 tok/s estimated Pays back in 82 years Run the numbers
Mac Studio M5 Max, 128GB $5,099 5.3 tok/s estimated Pays back in 67 years Run the numbers
MacBook Pro M5 Max (16-inch), 128GB $6,999 5.3 tok/s estimated Pays back in 91 years Run the numbers

One machine per family, cheapest first. Speeds are measured where a public benchmark exists and estimated from memory bandwidth otherwise; the calculator says which for any configuration.

The specifics

Parameters
125B
Quantisation
Q4_K_M
Weights on disk
75 GB
KV cache
12 GB at 32k context — Dense, all 88 layers full attention — the context cost is the highest on this list per token.
Maximum context
256k tokens (256k)
Licence
other (see repo)
Sources
source 1