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Can the Mac 128 GB run SDXL 1.0?

Yes. 16-bit fits on the Mac 128 GB with 108.3 GB to spare.

Image model · 3.5B128 GB unified · ~115.4 GB for the GPU · 300–800 GB/s · Apple SiliconData 2026-10-01
Runs well
Yes, with room to spare.

16-bit (6.9 GB) needs about 7.1 GB in use, so 108.3 GB of the 115.4 GB stays free: room for a larger image, a LoRA or a ControlNet.

Best file16-bit
File size6.9 GB
GPU memory needed~7.1 GB
Shared memory13 / 128 GB
Memory map · Mac 128 GB7.1 GB / 115.4 GB
058 GB115 GB
Weights 16-bit · 5.1 GBWorking memory · 1.2 GBReserve · 0.8 GBFree · 108.3 GB

01What to download

PartFileFolderSize
Checkpointsd_xl_base_1.0.safetensors
16-bit · stabilityai/stable-diffusion-xl-base-1.0
models/checkpoints6.9 GBDownload →
Total download · keep about the same free on disk6.9 GB

One file: the checkpoint already contains the text encoders and the VAE. 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 12.9 GB of your 128 GB. On this machine the model, the text encoder, the VAE and the operating system all use the same memory. That leaves room, so nothing has to be swapped to disk. calculated

02Every SDXL file on 115.4 GB

FileSizeNeededOn this cardQualityDownload
16-bit ←
SAFETENSORS · stabilityai
6.9 GB7.1 GBfits · 108.3 GB sparethe original weightsHugging Face →

“Needed” adds 1.2 GB of working memory for SDXL and a 0.8 GB reserve. Sizes 2026-10-01. The 6.94 GB checkpoint also holds the two text encoders and the VAE. During sampling only the UNet (about 5.1 GB at 16-bit, 2.6B parameters) has to sit in VRAM, so that is the figure used for the 16-bit file.

03The text encoder

The text encoder is inside the checkpoint, so there is nothing extra to download.

04Measured and reported results

Nobody has sent measured numbers for this pair yet. If you run SDXL on a Mac 128 GB, send your time per image and peak VRAM and it will appear here, credited.

05About the Mac 128 GB

A Mac with 128 GB shares that memory between the CPU and the GPU. On current macOS the GPU may use about 115.4 GB of it by default (older macOS versions: about 103.1 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 128 GB: M1 Ultra, M2 Ultra, M3 Max, M4 Max, M5 Max (memory bandwidth 300–800 GB/s - the higher, the faster). Everything about Macs and local AI →

128 GB unified · ~115.4 GB for the GPU · 300–800 GB/s · Apple Silicon. Everything that runs on it →

06Questions

How much VRAM does SDXL need?

Around 7.1 GB with the smallest file (16-bit).

Which SDXL file should I download for the Mac 128 GB?

16-bit (6.9 GB) from stabilityai/stable-diffusion-xl-base-1.0.

How much do I need to download for SDXL on the Mac 128 GB?

6.9 GB: sd_xl_base_1.0.safetensors.