Photoshop 21.0.2 slow on Mac Mini (Late 2014) macOS 10.15.2

[MRobertsMott]

I'm experiencing a lot of lag/drag when doing the following:

• Painting with normal paintbrush
• Selective mask dialogue/refine edge tool
• Blending brush

I'm a photographer working on 45MP images with multiple layers (TIFF or PSD) so the files do get quite large, but I'm hoping that I don't have to upgrade to a new computer.  Here's my specs:

I've tried doing pretty much everything recommended in the Optimize performance help page, with little to no noticable results.  Does anyone have any recommendations?

{Thread renamed by moderator}

[Sahil.Chawla]

Hi there,

Sorry to hear about the slow and laggy performacne of Photoshop, as you've already tried multiple troublesooting steps, could you please try deselecting "Use Graphics Processor" located in Photoshop's Preferences > Performance, then relaunch Photoshop and let us know if it helps?

Also, could you please try enabling "Legacy compositing" located in Photoshop's Preferences > Performance, then relaunch Photoshop and let us know if it helps?

Regards,
Sahil

[MRobertsMott]

Using your recommendations, here are my settings (I tried both, first one, then the other, then simultaneously), and the GIF attached shows the results.

[MRobertsMott]

As a note - I just tested the exact same settings in Photoshop 2019 CC and it worked flawlessly.

[BaronDuPotet]

Glad to see that I am not the only one experiencing that severe lag with brushes. I have a Mac Mini 2018 3.2Ghz and 64 Go RAM and it does the same thing. Have you try a solution other than buying an eGPU?