Mac Studio M5 Max: 48GB vs 64GB for local AI
The Mac Studio M5 Max, 64GB holds 38 of the 55 current models here, and the Mac Studio M5 Max, 48GB holds 37. The Mac Studio M5 Max, 48GB costs $400 less. On Qwen3.8 27B, the strongest model both hold, they run at much the same speed: 25 and 25 tok/s, both estimated from memory bandwidth. The Mac Studio M5 Max, 48GB pays for itself sooner, in 174 years against 197 years at 500k tokens a day.
| Mac Studio M5 Max, 48GB | Mac Studio M5 Max, 64GB | |
|---|---|---|
| Price | $3,099 | $3,499 |
| Memory | 48 GB | 64 GB |
| Usable by the GPU | 36 GB | 48 GB |
| Memory bandwidth | 614 GB/s | 614 GB/s |
| Power under load | 145 Wstand-in | 145 Wstand-in |
| Models that fit | 37 | 38 |
| Best model it runs | Qwen3.8 27B | Qwen3.8 27B |
| Speed on that model | 25 tok/s estimated | 25 tok/s estimated |
| Pay-back on that model | Pays back in 174 years | Pays back in 197 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 Mac Studio M5 Max, 48GB · or the Mac Studio M5 Max, 64GB
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 Qwen3.8 27B, the strongest model both hold, at the five levels of use the calculator names. The Mac Studio M5 Max, 48GB 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 use | Mac Studio M5 Max, 48GB | Mac Studio M5 Max, 64GB |
|---|---|---|
| 50ka few chats a day | 1,742 years | 1,967 years |
| 200klight assistant use | 436 years | 492 years |
| 1Ma moderate coding-assistant day | 87 years | 98 years |
| 4Mheavy coding with an agent | 22 years | 25 years |
| 20Magents running most of the day | 4.4 years | 4.9 years |
Run the Mac Studio M5 Max, 48GB at 20M tokens a day · or the Mac Studio M5 Max, 64GB
What the extra memory buys
The Mac Studio M5 Max, 64GB holds 1 model the Mac Studio M5 Max, 48GB cannot at 32k of context. That is what the difference in memory actually buys.
| Model | Weights | Needs at 32k | On the Mac Studio M5 Max, 64GB |
|---|---|---|---|
| Ripple 65B Previewnot yet placed | 39 GB | 41 GB | 11 tok/s estimated |
The extra memory buys context as well. Of the 37 current models both machines hold at 32k, 4 run to a longer window on the Mac Studio M5 Max, 64GB: the weights are a fixed size and the KV cache is not, so what the weights leave spare is what a longer context grows into. Gemma 4 31B it reaches 256k there against 128k on the Mac Studio M5 Max, 48GB, each the longest window the calculator offers that the machine still holds it at.
The Mac Studio M5 Max, 48GB is also head to head with another computer: MacBook Pro M5 Pro (16-inch), 24GB. With the same machine at another memory size: 128GB. With the same box and the smaller chip: 36GB. With the machine it replaced: Mac Studio M4 Max, 48GB.
The Mac Studio M5 Max, 64GB is also head to head with another computer: GMKtec EVO-X2, 128GB · Framework Desktop, 128GB. With the same machine at another memory size: 128GB. With the machine it replaced: Mac Studio M4 Max, 64GB.
Both sizes have a page of their own, with every machine here sold at that size, the models that fit it and what one step of memory buys: what 48 GB runs · what 64 GB runs.
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. Change any of it in the calculator.
More head to head: everything the Mac Studio M5 Max, 48GB runs · everything the Mac Studio M5 Max, 64GB runs · every other match-up · the quickest pay-back at each level of use · every model against the frontier