What to try when Photoshop feels slow

Photoshop was running a little sluggishly on my Mac, so I went through the settings that have the largest effect on performance. You do not need to apply all of them. Start with the bottleneck you actually have—memory, scratch-disk activity, or expensive document settings—and change one thing at a time.

Give Photoshop enough memory

The Memory Usage section in Photoshop’s Performance preferences shows the available RAM, its recommended allocation range, and the amount currently assigned to Photoshop. The default is 70%.

Open Edit → Preferences → Performance on Windows or Photoshop → Preferences → Performance on macOS. Increasing the allocation may help with large documents, but giving Photoshop 100% leaves no room for the operating system or other applications. That can make the whole computer slower, which is a rather unhelpful optimisation.

Use a 64-bit version of Photoshop when possible. It can address considerably more memory than an older 32-bit version.

Check the scratch disk

When Photoshop cannot keep everything in RAM, it uses disk space as a scratch disk. A fast SSD is the best option. Using a separate physical disk can also prevent Photoshop’s temporary work from competing with the operating system on the primary drive.

Choose the scratch disk in the same Performance preferences panel. Make sure it has plenty of free space; even a fast disk behaves badly when it is nearly full.

Keep fewer history states

Photoshop can store up to 1,000 history states, although the default is 20. Every state needs memory and scratch-disk space.

In Preferences → Performance, find History & Cache → History States and lower the number if you rarely step far back through an edit. This is a trade-off, not a free speed increase. Fewer states also mean fewer chances to undo an enthusiastic mistake.

Match the cache to the work

Higher cache levels can make Photoshop more responsive while editing large images, though opening a document may take longer. Cache tile size controls how much image data Photoshop processes at once.

Both settings live under History & Cache. There is no perfect value for every workflow: large photographs and many small layers put different demands on the cache. Try the preset closest to your work and compare it with a real document rather than an empty canvas.

Purge only when you need to

Edit → Purge → All clears history states and clipboard data. This can release a useful amount of memory after copying a large image or building up a long history.

Purging cannot be undone, so save first and make sure you no longer need those states. On macOS, holding Option while choosing About Photoshop—or Alt on Windows—also purges data.

Reduce panel previews

Layer thumbnails are convenient, but Photoshop has to keep updating them. Open the Layers panel menu, choose Panel Options, and select a smaller thumbnail or None.

This works best if layers are named and grouped. A fast panel containing 80 layers called “Layer copy 12” is not much of a victory.

Close documents you are not using

Each open image consumes memory. If Photoshop reports that it is out of RAM, or performance gets worse over a long session, close documents that are no longer needed.

Also look at other memory-heavy applications. Adjusting Photoshop’s allocation has limited value if several large applications are competing for the same RAM.

Watch the efficiency indicator

Choose Efficiency from the status-bar menu at the bottom of a document window. This shows whether Photoshop is doing most of its work in memory or repeatedly using the scratch disk.

If efficiency normally stays above 95%, buying a faster scratch disk is unlikely to make much difference. A consistently lower number is a clue that memory or disk access deserves attention.

Keep GPU support healthy

Photoshop uses GPU acceleration for screen drawing and several processing features. Check the graphics settings in the Performance preferences and keep the video driver current.

If display glitches started after a driver or Photoshop update, temporarily disabling GPU acceleration is also a useful diagnostic step. Faster is not useful if it draws the document incorrectly.

Turn off font previews

Large font libraries can slow down font menus. To disable WYSIWYG previews, choose Type → Font Preview Size → None.

This will not transform every workflow, but it is a cheap change if the delay appears mainly while working with type.

Use 8-bit colour when it is enough

Photoshop supports 16-bit and 32-bit images, but those modes require more memory and processing. If the work does not need the extra colour information—for example, it is not professional colour correction or print preparation—8 bits per channel may be enough.

Choose Image → Mode → 8 Bits/Channel to convert the document. Do this only when the reduced bit depth suits the final output, ideally on a copy. Performance settings can be reversed; discarded image data cannot.

I would begin with free disk space, the efficiency indicator, and open documents before buying hardware. Those checks usually tell you whether Photoshop needs more RAM, a faster scratch disk, or simply a less crowded afternoon.