I have been trying to get to the bottom of this issue on my own, but to no avail. I am running Photoshop CS5.1 Extended on an iMac with an i7, 16 GB of RAM and an AMD Radeon HD 6970M 2048 MB graphic card. I am running OSX Lion. Speed of the computer should NOT be an issue, but my liquify tool is impossibly slow. I have seen others having this issue, but am not finding resolutions. I have updated all of my software (Lion, CS5) and updated my drivers. I have uninstalled Photoshop and reinstalled it, but still, no help.
My Liquify tool is so slow that it is impossible to use. It does not register if I release the mouse either and I often have to click a few times to release the brush. I have Photoshop 5.1 on a PC and the Liquify runs very smoothly.
Has this issue been addressed? I am wondering if it has a root in how CS5 is reacting to the graphics card? When I called Adobe, they swore it was Apple's fault. When I talked to Apple, they were positive the blame lay with Adobe. I just want a fix. (Hey, I'll take a CS6 beta if that'll fix it. )
Do you have any third party plugins installed? If so, have you tried disabling them? (one was showng to cause a slowdown, but I don't have my office notes handy at the moment to remember which one)
Also, there was one obscure third party utiliity program (haxie) that also caused slowdowns in Liquify. (and again, my notes are at the office, so I don't recall the name)
And you can try the usual: trash/reset Photoshop's preferences.
Oh, and Lion still has a bunch of video driver bugs that Apple is continuing to work on.
Sorry I don't have more definite info right now.
No third party plug-ins. I do have some actions, but it was behaving badly before the actions were in the palette. I have reset preferences as well.
My business partner has nearly the same machine I do, and her Liquify is fine, the Graphics card is the main difference, so that is what was making me wonder if there was any specific info on if this particular graphics card had any other complaints.