---
id: mac-storage-basics.how-do-i-move-photoshop-scratch-disk
url: https://storagestudio.us/faq/mac-storage-basics/how-do-i-move-photoshop-scratch-disk
category: "Mac storage basics"
subcategory: "Caches, logs and temporary files"
question: "How do I stop Photoshop filling my startup disk with scratch files?"
alt_questions:
  - "photoshop scratch disk full mac"
  - "scratch disks are full"
  - "change scratch disk external drive"
  - "photoshop temp files mac"
  - "photoshop scratch disk settings"
short_answer: "In Photoshop → Settings → Scratch Disks, choose a fast external drive instead of the startup disk and restart Photoshop. Scratch files are removed when it quits."
tags: ["photoshop", "scratch disk", "adobe"]
related: ["https://storagestudio.us/faq/mac-storage-basics/what-is-the-temporary-folder-on-a-mac"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# How do I stop Photoshop filling my startup disk with scratch files?

Photoshop uses free disk space as temporary memory (the **scratch disk**). In **Photoshop → Settings → Scratch Disks**, tick a fast external drive and untick your startup disk if it's short of space. Restart Photoshop to apply.

Scratch files are normally removed when Photoshop quits; leftovers after a crash disappear when you restart the Mac. A "scratch disks are full" error usually means the startup disk itself is nearly full.