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

MacBook Pro M5 (14-inch): 16GB vs 32GB for local AI

The MacBook Pro M5 (14-inch), 32GB holds 19 of the 39 open models here, and the MacBook Pro M5 (14-inch), 16GB holds 10. The MacBook Pro M5 (14-inch), 16GB costs $400 less. On Gemma 4 12B, the strongest model both hold, they run at much the same speed: 14 and 14 tok/s, both estimated from memory bandwidth. The MacBook Pro M5 (14-inch), 32GB pays for itself sooner, in 31 years against 157 years at 500k tokens a day, though that is each machine on its own strongest model rather than on the same one.

MacBook Pro M5 (14-inch), 16GBMacBook Pro M5 (14-inch), 32GB
Price$1,999$2,399
Memory16 GB32 GB
Usable by the GPU10.5 GB21 GB
Memory bandwidth153 GB/s153 GB/s
Power under load65 Wstand-in65 Wstand-in
Models that fit1019
Best model it runsGemma 4 12BQwen3.8 27B
Speed on that model14 tok/s estimatedGemma 4 12B6.2 tok/s estimatedQwen3.8 27B
Pay-back on that modelPays back in 157 yearsPays back in 31 years

Neither power figure above is measured on the machine beside it. Both are stand-ins borrowed from the nearest hardware the data does have, so what the row shows is one borrowed figure printed twice. Each machine's page names the figure it borrows and why. Every pay-back figure on this page prices its electricity from these numbers.

Run the numbers on the MacBook Pro M5 (14-inch), 16GB · or the MacBook Pro M5 (14-inch), 32GB

Side by side on Gemma 4 12B

The table above gives each machine the strongest model it can hold, and those are not the same model, so the two speeds in it are not a race. Gemma 4 12B is the strongest model both machines hold, so this is the pair running the same work.

MacBook Pro M5 (14-inch), 16GBMacBook Pro M5 (14-inch), 32GB
Speed14 tok/s estimated14 tok/s estimated
Pay-backPays back in 157 yearsPays back in 188 years

Run Gemma 4 12B on the MacBook Pro M5 (14-inch), 16GB · or on the MacBook Pro M5 (14-inch), 32GB

How much use it takes to pay back

Everything above is at 500k tokens a day. Pay-back moves with how much you actually run, so here are both machines on the same model, at the five levels of use the calculator names. The MacBook Pro M5 (14-inch), 16GB pays back sooner at every level of use, so this is not a choice that turns on how hard you work it.

A day's useMacBook Pro M5 (14-inch), 16GBMacBook Pro M5 (14-inch), 32GB
50ka few chats a day1,569 years1,883 years
200klight assistant use392 years471 years
1Ma moderate coding-assistant day78 years94 years
4Mheavy coding with an agent20 years24 years
20Magents running most of the day4.0 yearsits ceiling4.7 yearsits ceiling

On Gemma 4 12B neither machine can generate 20M tokens a day: the MacBook Pro M5 (14-inch), 16GB manages at most 19.8M and the MacBook Pro M5 (14-inch), 32GB at most 19.8M. Both figures on that row are for the most each can do.

Run the MacBook Pro M5 (14-inch), 16GB at 20M tokens a day · or the MacBook Pro M5 (14-inch), 32GB

What the extra memory buys

The MacBook Pro M5 (14-inch), 32GB holds 9 models the MacBook Pro M5 (14-inch), 16GB cannot at 32k of context. The strongest of them are what the difference in memory actually buys.

ModelWeightsNeeds at 32kOn the MacBook Pro M5 (14-inch), 32GB
Qwen3.8 27BSonnet-class16 GB19 GB6.2 tok/s estimated
Qwen3.6 27BHaiku-class17 GB19 GB6 tok/s estimated
Muse Glimmer 30BHaiku-class17 GB18 GB6.4 tok/s estimated
Gemma 4 26B-A4BHaiku-class17 GB18 GB13 tok/s estimated
GLM-4.7-FlashHaiku-class18 GB20 GB13 tok/s estimated
Granite 4.2 8BBelow every hosted tier5.3 GB11 GB11 tok/s estimated

3 more, on the MacBook Pro M5 (14-inch), 32GB page.

The assumptions behind both columns

Both columns use the same usage: 500k tokens a day at 15:1 input to output, 32k of context, $0.17 per kWh, and today's API prices held flat. Speeds marked estimated are worked out from memory bandwidth rather than measured, and pay-back scales with them. Graphics cards are priced as the card alone, so add the PC around one before comparing it with a complete computer. Change any of it in the calculator.

More head to head: everything the MacBook Pro M5 (14-inch), 16GB runs · everything the MacBook Pro M5 (14-inch), 32GB runs · every other match-up · the quickest pay-back at each level of use · every model against the frontier