Maintainer tested1 successful reportsReviewed 2026-08-16

Generate a Stable Diffusion 1.5 image on an Apple M-series Mac with 16GB

A conservative first-run path using Comfy Desktop, the MPS backend, the official Stable Diffusion 1.5 FP16 checkpoint, and ComfyUI's built-in image workflow.

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Evidence status

Maintainer-verified on a 16GB MacBook Pro M4 with Comfy Desktop 1.0.37 and Apple MPS. The exact 512x512 baseline completed in 37.06 seconds; the current Desktop build required the reviewed core-workflow fallback because the built-in template was not listed.

Requirements

  • Apple Silicon Mac (M1 or later)
  • macOS 13 Ventura or later
  • 16GB unified memory with other memory-heavy apps closed
  • At least 20GB free disk space for the application, model, cache, and initial outputs

Stack

Application and workflow engine
Comfy Desktop · Current stable desktop release

The official macOS desktop build supports Apple Silicon and manages its own Python environment.

Acceleration backend
Apple MPS / Metal · Managed by Comfy Desktop

Choose MPS during setup; CPU mode is a fallback, not the intended path.

Model source
Stable Diffusion 1.5 · Official FP16 checkpoint

Use the FP16 checkpoint named in ComfyUI's official first-generation guide and review its CreativeML Open RAIL-M license before use.

Workflow
Built-in Image Generation template · Current ComfyUI core template

Use a core template first; do not add third-party custom nodes until the baseline run succeeds.

Agent-assisted mode

Run this recipe with your AI agent

Copy one instruction to your agent. It will read the Skill, use its supported installation method, run the recipe, verify the result, and prepare the same structured report as the manual flow below.

Give this Skill to your agentNo agent selection required
Install and run this LocalAIRun Skill.

Skill: localairun-sd15-mac
Skill source: https://localairun.com/skills/localairun-sd15-mac/SKILL.md
Recipe: https://localairun.com/recipes/apple-m4-16gb-sd15-comfy-desktop/
Recipe version: 2026.08.2

Read SKILL.md before making changes. Use your supported Skill installation method; if you do not support persistent Skills, load and follow it for this run. Check compatibility first, explain each system change, and ask before downloads, application installation, launches, or file changes. Run the baseline verification and help me submit the structured result when finished.
Review SKILL.md

The agent should install the Skill when it supports persistent Skills. Otherwise, it can load the same SKILL.md for this run without changing the recipe.

What the Skill will do

  1. 1

    Check before installing

    Verifies Apple Silicon, macOS version, unified memory, and available disk space.

  2. 2

    Use the exact stack

    Keeps Comfy Desktop, Apple MPS, the reviewed FP16 checkpoint, and its SHA-256 together.

  3. 3

    Run a comparable test

    Applies the same prompt, seed, resolution, and success criteria used by this recipe.

  4. 4

    Return evidence

    Compares the actual Skill run with the manual steps and prepares a structured result or workflow-difference report.

User approval remains required

The Skill checks first and pauses before large downloads, application installation, launches, or file changes. It never uses sudo or bypasses macOS security.

Manual mode

Step-by-step execution

0 / 6 complete

Use the same safeguards as the Skill

Check the machine first, use only the linked official sources, confirm large downloads and file locations, and do not bypass macOS security. Mark a step complete only after its check passes.

  1. 1. Verify your Mac before installing

    • •Open Terminal and run: uname -m. The result must be arm64.
    • •Run: sw_vers -productVersion. This recipe requires macOS 13 or later.
    • •Run: sysctl -n hw.memsize. A 16GB Mac normally reports 17179869184 or more.
    • •Run: df -h "$HOME". Confirm that at least 20GB is available before downloading anything.
    Check: Architecture is arm64, macOS is 13 or later, memory is at least 16GB, and free disk space is at least 20GB. Stop here if any check fails.

  2. 2. Install or verify Comfy Desktop

    Official instructions →
    • •If Comfy Desktop is already installed, launch it and confirm it opens normally before changing anything.
    • •Otherwise, download the current macOS installer only from the official ComfyUI documentation linked here.
    • •Install and launch Comfy Desktop, then create its managed local ComfyUI installation.
    • •Select MPS when the accelerator option is shown; CPU-only mode is not the intended path for this recipe.
    • •If a command-line signature diagnostic is inconclusive but the installer came from the official ComfyUI source, do not disable Gatekeeper or bypass a macOS warning. Complete the normal Finder installation manually and continue only when the official app launches normally.
    Check: ComfyUI opens without an installation or backend error and uses MPS rather than CPU-only mode.

  3. 3. Load the core image workflow

    Official instructions →
    • •Open Workflow, then Browse Workflow Templates.
    • •Choose the built-in Image Generation template.
    • •If the current Comfy Desktop template browser does not show Image Generation, download the reviewed LocalAIRun core workflow from /workflows/apple-m4-16gb-sd15-comfy-desktop.json, import it, and refresh the workflow list.
    • •Keep the initial workflow free of third-party custom nodes.
    Check: The workflow graph loads and only core nodes are reported.

  4. 4. Install and verify the exact checkpoint

    Official instructions →
    • •In Comfy Desktop, use Help, Open folder, then Open models folder. Confirm the actual checkpoints directory instead of guessing its location.
    • •After confirming the approximately 2.13GB download, download v1-5-pruned-emaonly-fp16.safetensors from the official Comfy-Org file link below.
    • •Place the file in the confirmed checkpoints folder, then run: shasum -a 256 /path/to/v1-5-pruned-emaonly-fp16.safetensors.
    • •The SHA-256 must be e9476a13728cd75d8279f6ec8bad753a66a1957ca375a1464dc63b37db6e3916. Delete the incomplete or mismatched file and stop if it differs.
    • •Refresh model definitions or restart ComfyUI after the hash matches.
    Check: The SHA-256 matches and v1-5-pruned-emaonly-fp16.safetensors appears in the Load Checkpoint node without a missing-model warning.

  5. 5. Generate the baseline image

    • •Apply every baseline setting shown below, including the fixed prompt and seed. Do not change resolution, batch size, sampler, or scheduler for this first test.
    • •Close other memory-heavy applications before the first run.
    • •Click Run or press Command + Enter and wait for one image to complete.
    Check: One image is saved without an out-of-memory, missing-node, or model-load error.

  6. 6. Record and report the result

    • •Record the Mac model and memory, macOS version, Comfy Desktop version, checkpoint status, and whether the image completed.
    • •Also record time to first image, memory pressure or swap if observed, and the final error line if the run failed.
    • •Remove account names, private paths, prompts, and unrelated logs before submitting the structured success or failure report.
    Check: The report contains enough version and hardware detail for another person to reproduce the run.

Baseline settings

width
512
height
512
batch size
1
steps
20
cfg
7
sampler
euler
scheduler
normal

Comparable test

Prompt

A small reading room beside a rain-covered window, warm practical lighting, realistic photography, detailed textures

Seed: 20260807

Did it run on your hardware?

Success and failure reports both improve this recipe's evidence level.

Submit test result

Sources

Comfy Desktop for macOS →ComfyUI first image generation →Stable Diffusion 1.5 FP16 checkpoint →OpenAI Agent Skills documentation →