anyone having similar high CPU load on mavericks?
What is a normal CPU % to be doing simple things in Photoshop? Like just drawing with a brush..
The only such problem I know of happens if you have color samplers active and the info palette visible. Otherwise Photoshop's CPU usage goes down to about 1% in the background.
While you are actively using Photoshop, the CPU usage will be higher, of course.
Haven't yet solved this problem, and am not sure if it is solvable. I found a thread (older) where people were discussing the same sort of thing:
Yes, I do. Anyone that uses Photoshop on Mac can confirm this. For example, open Activity Monitor, switch to Photoshop, create a new document, and hold down the mouse button with for example the selection tool.
Result? 50-100% CPU usage.
Photoshop probably contains a lot of old, legacy code. The user interface is a real CPU hog. The programmers cannot be proud of this, and I wouldn't be surprised if the next version (CS5?) addresses this. They are going to rewrite in Cocoa, I heard.
While holdinw down the mouse, Photoshop is actively tracking the mouse and getting updates from the OS. That has nothing to do with legacy code, and Cocoa has nothing to do with it.