Can the Mac 16 GB run FLUX.2 [dev]?
Not entirely. Even Q4_K_M is 10.7 GB over 12.7 GB, so ComfyUI keeps part of it in system RAM.
The smallest sensible file, Q4_K_M (20.1 GB), needs about 23.4 GB - 10.7 GB more than Mac 16 GB has. ComfyUI can still run it by streaming part of the model from system RAM. How much slower that is depends on your ComfyUI version, the file format and the PCIe link - see the note below.
01With more VRAM
With 48 GB you could run FLUX.2 dev at 8-bit or better (Q8_0, 35.0 GB) with no offloading.
02Every FLUX.2 dev file on 12.7 GB
| File | Size | Needed | On this card | Quality | Download |
|---|---|---|---|---|---|
| 16-bit SAFETENSORS · black-forest-labs | 64.4 GB | 67.7 GB | 55.0 GB too big | the original weights | Hugging Face → |
| Q8_0 GGUF · city96 | 35.0 GB | 38.3 GB | 25.6 GB too big | practically identical to the original | Hugging Face → |
| Q6_K GGUF · city96 | 27.4 GB | 30.7 GB | 18.0 GB too big | very close to the original | Hugging Face → |
| Q5_K_M GGUF · city96 | 24.1 GB | 27.4 GB | 14.7 GB too big | close; small differences in fine detail | Hugging Face → |
| Q4_K_M ← GGUF · city96 | 20.1 GB | 23.4 GB | 10.7 GB too big | good; some loss in fine detail and text | Hugging Face → |
| Q3_K_M GGUF · city96 | 16.0 GB | 19.3 GB | 6.6 GB too big | noticeable loss of detail | Hugging Face → |
| Q2_K GGUF · city96 | 12.9 GB | 16.2 GB | 3.5 GB too big | heavy loss; a last resort | Hugging Face → |
“Needed” adds 2.5 GB of working memory for FLUX.2 dev and a 0.8 GB reserve. Sizes 2026-10-01. FP8 and INT8 files are left out on a Mac: Apple GPUs cannot compute FP8, so ComfyUI either fails to load them or converts them back to 16-bit, which saves no memory. Use a 16-bit or GGUF file.
03What to download
| Part | File | Folder | Size | |
|---|---|---|---|---|
| Model | flux2-dev-Q4_K_M.gguf Q4_K_M · city96/FLUX.2-dev-gguf | models/unet | 20.1 GB | Download → |
| Text encoder | mistral_3_small_flux2_bf16.safetensors Mistral 3 Small BF16 · Comfy-Org/flux2-dev | models/text_encoders | 35.6 GB | Download → |
| VAE | flux2-vae.safetensors FLUX.2 VAE · Comfy-Org/flux2-dev | models/vae | 0.3 GB | Download → |
| Total download · keep about the same free on disk | 56.0 GB | |||
On a Mac, FP8 text encoders do not load, so a 16-bit one is listed. Sizes from Hugging Face, 2026-10-01.
Shared memory: about 62.0 GB of your 16 GB. On this machine the model, the text encoder, the VAE and the operating system all use the same memory. That is about 46.0 GB more than there is. It still runs: while the model works, the system compresses or swaps the idle text encoder, so loading and changing the prompt get slower. A smaller file or text encoder avoids that. calculated
04The text encoder
At 18.0 GB even the smallest Mistral Small 3 (24B) file is too big for 12.7 GB, so it runs from system RAM. That slows down reading the prompt, not the picture. Sizes: 16-bit 35.6 GB, FP8 18.0 GB. Why the encoder does not count against VRAM →
05Measured and reported results
Nobody has sent measured numbers for this pair yet. If you run FLUX.2 dev on a Mac 16 GB, send your time per image and peak VRAM and it will appear here, credited.
06About the Mac 16 GB
A Mac with 16 GB shares that memory between the CPU and the GPU. On current macOS the GPU may use about 12.7 GB of it by default (older macOS versions: about 11.5 GB); that is the figure used here. ComfyUI can go past it, but macOS then starts compressing and swapping memory and everything slows down. ComfyUI runs on Apple GPUs through PyTorch's MPS backend. 16-bit and GGUF files work; FP8 and INT8 files do not save memory on a Mac, so they are skipped. Speed is the catch: even the fastest Macs are several times slower per image than a desktop RTX card. Chips sold with 16 GB: M1, M1 Pro, M2, M2 Pro, M3, M4, M5, M6 (memory bandwidth 68.25–200 GB/s - the higher, the faster). Everything about Macs and local AI →
16 GB unified · ~12.7 GB for the GPU · 68.25–200 GB/s · Apple Silicon. Everything that runs on it →
07Questions
How much VRAM does FLUX.2 dev need?
Around 16.2 GB with the smallest file (Q2_K) and 38.8 GB with an 8-bit file (FP8). The full 16-bit file needs about 67.7 GB.
Which FLUX.2 dev file should I download for the Mac 16 GB?
Q4_K_M (20.1 GB) from city96/FLUX.2-dev-gguf. Load it with Unet Loader (GGUF) from the ComfyUI-GGUF node pack.
FP8 or Q8_0 for FLUX.2 dev on the Mac 16 GB?
Q8_0 (35.0 GB). The Mac 16 GB has no FP8 maths, so FP8 (35.5 GB) only saves memory and is a step further from the original.
How much do I need to download for FLUX.2 dev on the Mac 16 GB?
56.0 GB: flux2-dev-Q4_K_M.gguf, mistral_3_small_flux2_bf16.safetensors, flux2-vae.safetensors.