This afternoon, I was trying to figure out why the UI for BottomFeeder was crawling on the Mac. Actions that were nearly instantaneous on Windows took a noticeable amount of time on the Mac. I was thinking it must be some horrid VM issue, but then I got a simple suggestion from Alan Knight, our engineering manager: stop using the DoubleBufferingWindowDisplayPolicy.

As it happens, the Cocoa libraries on the Mac solve that problem for you - so doing it yourself just adds overhead. When I removed that policy from the UI opening, suddenly the entire problem went away.

So - if you're testing your VisualWorks application on Mac, and you notice that things are really, really slow - check to see whether you set the window to use the double buffering policy. If you did, pull that and the problem will likely go away.

Technorati Tags: mac, OSX, cocoa