Could you share a sample file so we can see the volume of paths you are creating and possibly I can test zooming on my machine to see if it compares?
I've sent my file to your email link just because I can't show it on a public forum yet, so your discretion would be appreciated.
Hi Gary, it hasn't come across yet.
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I've found out a bit more about this Mark.
It seems dragging the image window over to my non-Retina 24" 1920 x 1200 second screen solves it, the scrubby zoom is smooth. It's looking like the Retina 27" iMac screen at 5120 x 2880 is struggling to redraw the pathing in real time even with 4GB onboard the Radeon Pro 570.
I guess there must be so much info in rendering the paths in CC19 compared to last years previous version. I really thought turning off 'Anti-alias Guides and Paths' might solve a problem like this but it'll take someone with a better specced iMac GPU to prove a fast card redraw overcomes this.
I also got speed issues in Photoshop CC using paths on Mac.
When I do the same thing on PC it works without any problems.
But when I use paths on the Mac version it's extremely slow.
Only entirely disabling GPU in Photoshop solves that problem.
But then the rest of Photoshop is getting sluggish.
Path issue is on Mac Pro 2009 with a new graphic card Nvidia GTX 1050 Ti.
I also tested it on Macbook Pro 2017 with Radeon 4GB RAM.
It's even much worse there.
A friend of mine has the same problem on an older Macbook Pro.