If been having issues where when I enter coherence mode all the windows are blank white. It seem intermittent, but I finally narrowed it down to the integrated graphics. Basically, coherence mode doesn't work at all on integrated graphics. This happens on Parallels Desktop 7 & 8. Is this intentional? I have gfxcardstatus installed so I can manually chose which graphics card I want to use. Does Parallels automatically switch on dedicated graphics in coherence mode (when gfxcardstatus is not installed)? This is with a Windows 7 64-bit VM on a Macbook Pro Retina running 10.8.
First of all, forcing either graphics chip with gfxCardStatus when you have open applications is a very, very bad idea, unless you're absolutely know what you're doing. If those applications don't support switchable graphics they will still be using the chip they started on, and may misbehave (White windows in Coherence.). Other applications will use the new setting. So, your Mac may end up running *both* chips. Not only will this drain battery faster, this might cause overheating and even physical damage to the chips. Now, back to your original question. I guess, what you actually want to do is to save battery. Parallels Desktop perfectly supports OS X graphics switching, you just need to enable Longer battery life in VM Configuration > Options > Optimization > Power, before starting the VM. With that setting you'll even be able to force graphics chips using gfxCardStatus, but I strongly recommend against that. Let OS X manage your graphics and use the app to monitor current state only.
Thanks! Enabling the "longer battery life" feature seemed to have worked. I can stop using gfxcardstatus if it's going to cause issues, although I've never had any problems outside parallels. It would have been nice if it was a bit more transparent as to what the "longer battery life" feature did. That would have saved me some trouble.
