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

Mac Studio M5 Max, 128GB vs AMD Radeon AI PRO R9700, 32GB for local AI

The Mac Studio M5 Max, 128GB holds 40 of the 49 current models here, and the Radeon AI PRO R9700, 32GB holds 33. The Radeon AI PRO R9700, 32GB costs $3,800 less, though the Radeon AI PRO R9700, 32GB is priced as the card alone, without the PC around it. On Qwen3.8 27B, the strongest model both hold, the Radeon AI PRO R9700, 32GB is about 1.2× faster: 30 tok/s against 25, both estimated from memory bandwidth. The Radeon AI PRO R9700, 32GB pays for itself sooner, in 84 years against 287 years at 500k tokens a day.

Mac Studio M5 Max, 128GBAMD Radeon AI PRO R9700, 32GB
Price$5,099$1,299card only
Memory128 GB32 GB
Usable by the GPU96 GB31 GB
Memory bandwidth614 GB/s640 GB/s
Power under load145 Wstand-in300 W
Models that fit4033
Best model it runsQwen3.8 27BQwen3.8 27B
Speed on that model25 tok/s estimated30 tok/s estimated
Pay-back on that modelPays back in 287 yearsPays back in 84 years

The 145 W beside the Mac Studio M5 Max, 128GB is a stand-in, not a figure for that machine: the data borrows it from the nearest hardware it does have, and the machine's own page names which and why. So the two figures above are not like for like, and the electricity in its pay-back here is priced from a borrowed number.

Run the numbers on the Mac Studio M5 Max, 128GB · or the AMD Radeon AI PRO R9700, 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 Qwen3.8 27B, the strongest model both hold, at the five levels of use the calculator names. The AMD Radeon AI PRO R9700, 32GB 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 useMac Studio M5 Max, 128GBAMD Radeon AI PRO R9700, 32GB
50ka few chats a day2,867 years836 years
200klight assistant use717 years209 years
1Ma moderate coding-assistant day143 years42 years
4Mheavy coding with an agent36 years10 years
20Magents running most of the day7.2 years2.1 years

Run the Mac Studio M5 Max, 128GB at 20M tokens a day · or the AMD Radeon AI PRO R9700, 32GB

What the extra memory buys

The Mac Studio M5 Max, 128GB holds 7 models the AMD Radeon AI PRO R9700, 32GB cannot at 32k of context. The strongest of them are what the difference in memory actually buys.

ModelWeightsNeeds at 32kOn the Mac Studio M5 Max, 128GB
Ling 3.0 flashHaiku-class78 GB78 GB53 tok/s estimated
Qwen3.5 122B-A10BHaiku-class78 GB79 GB26 tok/s estimated
gpt-oss-120bBelow every hosted tier63 GB65 GB46 tok/s estimated
Mistral Small 4 (119B-2603)Below every hosted tier74 GB75 GB41 tok/s estimated
Qwen3-Coder NextBelow every hosted tier48 GB49 GB70 tok/s estimated
Devstral 2 123BBelow every hosted tier75 GB87 GB5.3 tok/s estimated

1 more, on the Mac Studio M5 Max, 128GB page.

The extra memory buys context as well. Of the 33 current models both machines hold at 32k, 11 run to a longer window on the Mac Studio M5 Max, 128GB: 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. Nanbeige4.3 33B reaches 256k there against 32k on the AMD Radeon AI PRO R9700, 32GB, each the longest window the calculator offers that the machine still holds it at.

The Mac Studio M5 Max, 128GB is also head to head with another computer: Mac mini M5 Pro, 24GB · DGX Spark, 128GB · GMKtec EVO-X2, 128GB · MacBook Air M5 (15-inch), 16GB · MacBook Pro M5 Pro (16-inch), 64GB · MacBook Pro M5 Max (16-inch), 48GB. With a graphics card: RTX PRO 6000 Blackwell, 96GB. With the same machine at another memory size: 48GB · 64GB. With the machine it replaced: Mac Studio M4 Max, 128GB.

The Radeon AI PRO R9700, 32GB is also head to head with another card: RTX PRO 6000 Blackwell, 96GB · GeForce RTX 5090, 32GB · GeForce RTX 4090, 24GB · GeForce RTX 3090, 24GB · GeForce RTX 4080, 16GB · GeForce RTX 3060, 12GB. With a complete computer: Mac mini M5 Pro, 24GB · DGX Spark, 128GB · GMKtec EVO-X2, 128GB · MacBook Air M5 (15-inch), 16GB · MacBook Pro M5 Pro (16-inch), 64GB · Mac mini M6, 32GB.

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. The Radeon AI PRO R9700, 32GB is priced as the card alone, so add the PC around it before comparing it with a complete computer. All seven cards here are ranked by what each one holds. Change any of it in the calculator.

More head to head: everything the Mac Studio M5 Max, 128GB runs · everything the AMD Radeon AI PRO R9700, 32GB runs · every other match-up · the quickest pay-back at each level of use · every model against the frontier