Overview
For a local LLM, a Mac versus an NVIDIA PC comes down first to how much memory the model can sit in: Apple lists up to 512GB of unified memory on a Mac Studio with M5 Ultra (the 512GB configuration was still “coming in late October” per Apple’s newsroom), while NVIDIA’s pages list 24 GB (RTX 3090), 32 GB (RTX 5090) and 96 GB (RTX PRO 6000) of VRAM on a single card. Which one is faster for your model is unknown on this page: neither vendor publishes a comparable number and this site publishes no tokens-per-second figures. You can measure your own with measure-tokens-per-second-mac. Every spec below comes from a vendor page read on 2026-10-13 and is linked. The Mac-side explanation of the memory pool is unified-memory-vs-vram.
Mac vs NVIDIA for local LLM: what does each vendor list?
| Machine | Memory (vendor wording) | Memory bandwidth | Source |
|---|---|---|---|
| Mac Studio, M5 Max | 36GB base; 48GB, 64GB or 128GB | 460GB/s; 614GB/s with the 40-core GPU | Apple |
| Mac Studio, M5 Ultra | 96GB base; 256GB or 512GB | 1.2TB/s | Apple |
| Mac mini, M6 | 16GB; 24GB or 32GB | 153GB/s; 170GB/s | Apple |
| Mac mini, M5 Pro | 24GB; 48GB or 64GB | 307GB/s | Apple |
| 14-inch MacBook Pro, M5 | 16GB, 24GB or 32GB | 153GB/s | Apple |
| GeForce RTX 5090 | 32 GB GDDR7, 512-bit | not stated on the page | NVIDIA |
| GeForce RTX 3090 | 24 GB GDDR6X, 384-bit | not stated on the page | NVIDIA |
| RTX PRO 6000 (three editions) | 96 GB GDDR7 with ECC | not stated on the page | NVIDIA |
Apple’s bandwidth figures are Apple’s, not measurements. Apple’s Mac mini page lists two M6 numbers for what looks like the same chip, which is covered on apple-silicon-memory-bandwidth. The NVIDIA pages read give a bus width but no GB/s, so a bandwidth comparison between the two vendors is unknown from these sources. This site does not compute one from bus width, because the memory data rate is not stated on those pages.
Which models fit in a Mac and which fit in a GPU?
A model fits when total_GB = weights_GB + kv_GB + overhead_GB is below the memory it must live in, with weights_GB = params × bits / 8 / 1e9 as defined on methodology. Using the Qwen2.5 Instruct totals worked on how-much-ram-for-local-llm (2 GB overhead assumed, KV at 2 bytes per value):
| Model and setting | Total | RTX 3090 (24 GB) | RTX 5090 (32 GB) | RTX PRO 6000 (96 GB) | Mac Studio M5 Max, 64GB | M5 Ultra, 96GB |
|---|---|---|---|---|---|---|
| 32B, 4-bit, context 4096 | 19.324 GB | below | below | below | below | below |
| 72B, 4-bit, context 4096 | 39.692 GB | above | above | below | below | below |
| 72B, 8-bit, context 4096 | 76.042 GB | above | above | below | above | below |
| 72B, 8-bit, context 32768 | 85.437 GB | above | above | below | above | below |
“Below” means the total is under the listed capacity, before any reserve. For the Mac columns the share of unified memory the GPU may use is unknown (see mac-gpu-memory-limit), so a close fit is unconfirmed. For a PC the card’s VRAM is the limit for GPU-resident weights; what happens when a model spills into system RAM is not covered by the sources read, and speed in that case is unknown. The 85.437 GB row is 72.7 + 10.737 + 2 from mac-studio-llm. A 96GB figure for either machine leaves the 85.437 GB row only 10.563 GB of headroom (96 - 85.437), before the reserve.
The M5 Ultra at 256GB or 512GB and the M5 Max at 128GB hold everything in this table. Apple’s newsroom says the 512GB configuration “is coming in late October”, so by Apple’s wording it was not shipping on 2026-10-13 (newsroom). See m5-ultra-llm.
Mac Studio vs RTX 5090: which is the better local LLM machine?
It depends on model size, and the comparison here is capacity only. An RTX 5090 lists 32 GB; the Qwen2.5 32B 4-bit total of 19.324 GB is below it and the 72B 4-bit total of 39.692 GB is above it. A Mac Studio M5 Max configured with 64GB or 128GB is above the 72B 4-bit total. Speed on the models that fit both is unknown: NVIDIA’s page states no bandwidth and Apple states no generation speed. Apple does publish vendor claims on prompt processing in LM Studio against older Macs, which say nothing about an NVIDIA card. The GPU-first buying view is on the sister site: best GPU for local LLM and RTX 3090 vs 4090 vs 5090.
What does each cost and draw in power?
Apple’s newsroom gives U.S. starting prices of 5,499 with M5 Ultra, and the Mac Studio spec page lists “Maximum continuous power: 480W”. NVIDIA’s RTX 5090 page lists total graphics power of 575 W and a required system power of 1000 W, and shows a placeholder where the price would be, so the card’s price is unknown here. The RTX PRO 6000 page lists 600 W (Workstation), 300 W (Max-Q Workstation) and 400-600 W (Server) and no price. A full PC price needs a CPU, board, RAM and a supply as well; that is unknown here and the build side is on local LLM PC build. The memory you buy on a Mac is chosen at purchase and is the model’s whole budget; the upgrade path for a PC is not stated on the pages read.
Mac mini vs RTX 3090: how do the small ones compare?
On capacity, a 24 GB RTX 3090 and a 24GB Mac mini M5 Pro or 24GB M6 have the same listed number, and the 32B 4-bit total of 19.324 GB is below it on both (before any reserve). The Mac mini can be configured to 32GB (M6) or 64GB (M5 Pro), above any single 3090. Bandwidth for the 3090 is not stated on NVIDIA’s page, so that comparison is unknown. The 3090 page is for a card; the Mac is a complete computer. See mac-mini-llm.
Is a 32GB MacBook Pro better than a 16GB VRAM PC?
On capacity, yes by the numbers: Apple lists 32GB of unified memory on the 14-inch MacBook Pro with M5, versus 16 GB of VRAM. The 32B 4-bit total of 19.324 GB is above 16 GB and below 32GB. Whether macOS leaves that much for the GPU is unknown, so the margin is not confirmed. The RTX cards read on this page start at 24 GB, so a 16 GB card is not one this page has a source for.
What about Strix Halo, Framework Desktop and other PCs?
Some PCs also use one large memory pool. The Framework Desktop page lists 32GB, 64GB, 128GB and 192GB of LPDDR5X on a 256-bit bus, with AMD Ryzen AI Max processors. The page states no memory bandwidth in GB/s and no figure for how much of that memory the GPU may use, so both are unknown here and a Framework versus Mac Mini or Mac Studio comparison on speed cannot be made from it. AMD’s own Ryzen AI Max+ 395 product page returned an error when read on 2026-10-13, so no AMD figure is used. For a PC-only discrete-GPU versus unified-memory framing see mac-studio-vs-dgx-spark.
Questions
Is a Mac or NVIDIA better for local LLMs?
Neither wins on every axis, and the sources read do not support a speed ranking. By listed memory a Mac Studio reaches 96GB to 512GB (M5 Ultra) and a single NVIDIA card reaches 24 GB to 96 GB (RTX 3090 to RTX PRO 6000); speed is unknown.
Can a Mac run the same models as an NVIDIA GPU?
A model that fits in memory can be loaded on either, since the fit formula is the same; the memory it is compared against differs. The Qwen2.5 72B 4-bit total of 39.692 GB is above the 32 GB RTX 5090 and below a 64GB Mac Studio M5 Max.
How much VRAM do I need compared with Mac unified memory?
Use the same total: weights plus KV cache plus overhead from methodology. Compare it to VRAM on a GPU and to installed unified memory on a Mac, where the GPU-usable share is unknown.
Mac Studio vs RTX 5090 for LLM?
Capacity only: 32 GB on the RTX 5090 versus 36GB to 128GB (M5 Max) or 96GB to 512GB (M5 Ultra) on a Mac Studio. Speed is unknown and the RTX 5090 price is not stated on NVIDIA’s page.
Mac mini vs 3090 for LLM?
Both reach 24 GB, with the Mac mini configurable higher, and the 3090 page states no bandwidth, so speed is unknown. A mini is a whole computer; a 3090 is one part.
M5 Ultra vs RTX PRO 6000?
Apple lists 96GB base and up to 512GB of unified memory at 1.2TB/s; NVIDIA lists 96 GB GDDR7 and no bandwidth. Apple lists a U.S. starting price of $5,499 for the M5 Ultra Mac Studio; the RTX PRO 6000 page lists no price, so a cost comparison is unknown.
Is 32GB on a MacBook Pro better than 16GB of VRAM?
It is double the listed capacity. The unified memory is shared with macOS, and how much the GPU may use is unknown.
Does this page include benchmarks or tokens per second?
No. Neither vendor’s page read gives a comparable figure, and this site publishes none.
Sources read on 2026-10-13
- Apple Mac Studio specs: M5 Max and M5 Ultra memory, bandwidth, maximum continuous power 480W.
- Apple Mac mini specs: M6 and M5 Pro memory options and bandwidth.
- Apple MacBook Pro specs: M5 memory options and 153GB/s.
- Apple newsroom, new Mac Studio: U.S. starting prices, 512GB timing, vendor LM Studio prompt-processing claims against older Macs (not repeated).
- NVIDIA GeForce RTX 5090: 32 GB GDDR7, 512-bit, 575 W; no bandwidth or price.
- NVIDIA RTX 3090 and 3090 Ti: 24 GB GDDR6X, 384-bit; no bandwidth.
- NVIDIA RTX PRO 6000 family: 96 GB GDDR7 ECC and power by edition; no bandwidth.
- Framework Desktop: memory options, LPDDR5X, 256-bit bus; no bandwidth.
- methodology and how-much-ram-for-local-llm: fit formulas and Qwen2.5 totals.
- AMD Ryzen AI Max+ 395 product page: HTTP 503, nothing taken.