Mac Studio vs RTX 4090: which local AI box?
| Mac Studio M2 Ultra (64GB) | RTX 4090 | |
|---|---|---|
| Historical editorial estimate | $3,000 | $2,325 |
| eBay median (filtered) | — | — |
| Memory | 64GB unified | 24GB VRAM |
| $ / GB (sample median) | Unavailable | Unavailable |
| Power | ~50–300W system | 450W TDP |
| Launch MSRP | $3,999 | $1,599 |
Affiliate disclosure: Affiliate (paid) links: we may earn a commission from eBay Partner Network and Amazon Associates at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. Full disclosure.
Verify model fit before buying
Memory capacity alone cannot tell you which models run. Check the artifact, runtime, context and concurrency, including cache and working buffers. Mac memory is shared with the operating system. See our memory sizing guide.
We have not benchmarked these configurations. Hardware advice reviewed 2026-10-04. Check the sources below for supported hardware and software requirements.
Available memory matters
Mac unified memory is shared with macOS and applications. Leave room for the model, context and working buffers. The 64GB configuration is a candidate for larger artifacts, not a guarantee for every 70B model or context setting.
Runtime and performance
MLX LM and Metal-based applications support local inference on Apple silicon. CUDA-dependent workflows need compatible NVIDIA hardware. Compare the same artifact, precision and context; record prompt-processing time and generation speed separately.
A computer versus a component
The Mac price covers a complete computer; the 4090 price covers a card. Add the host PC and any power or cooling upgrades. Evaluate power at the wall under a matching workload rather than comparing GPU board power with a whole Mac.
Sources and review
FAQ
How do I know whether my model will fit?
Check the exact artifact, runtime, context and concurrency. Allow for cache and working memory; installed capacity alone is not a fit test.
Which is the better value today?
First confirm that the hardware supports your workload. Then compare dated asking-price samples, condition, checkout cost and any required system upgrades. Historical editorial fair values are not current offers.
Also consider
| Model | Memory | Fair value | eBay median |
|---|---|---|---|
| Mac Studio M2 Max (64GB) | 64GB | $2,000 | — |
| Mac Studio M2 Ultra (128GB) | 128GB | $4,200 | — |
| Mac mini M4 Pro (48GB) | 48GB | $1,625 | — |
| RTX 3090 | 24GB | $1,200 | — |
More comparisons
- RTX 5070 Ti vs RTX 4070 Ti Super: which should you buy?
- RTX 3090 vs RTX A6000: which should you buy?
- RTX 5060 Ti 16GB vs RTX 4060 Ti 16GB: which should you buy?
- RTX 3060 12GB vs RX 6700 XT: which should you buy?
- RTX 5070 Ti vs RX 9070 XT: 16GB alternatives for gaming and local AI
- RTX 5070 vs RX 9070: 12GB or 16GB for your next build?
- RTX 5060 Ti 16GB vs RX 9060 XT 16GB: compare the exact 16GB versions
- RTX 4070 Super vs RX 7800 XT: used value, 12GB vs 16GB and software
- RTX 4070 Ti Super vs RX 7900 XT: 16GB CUDA or 20GB Radeon?
- RTX 4080 Super vs RX 7900 XTX: 16GB vs 24GB for gaming and local AI
- RTX 3080 10GB vs RX 6800 XT: older used GPUs, memory and compatibility
- RTX 3090 vs RTX 4090: which used card for local AI?
- RTX 3090 vs RX 7900 XTX: 24GB CUDA vs 24GB ROCm
- RTX 4090 vs RTX 5090 for LLMs: is the upgrade worth it?
- RTX 3080 vs RTX 4070: cheap veteran or efficient successor?
- RTX 4080 vs RTX 4090: 16GB value or 24GB ceiling?
- RTX 5070 vs RTX 4070 Super: which 12GB card to buy used?