OS X: Disable your v-sync

This post falls under the heading of "maybe not the single greatest idea in the world, but perhaps not the worst either." As we all know, Apple, in its infinite wisdom put some (ok, lots of) extra eye candy into OS X when it leaped from 10.4 to 10.5, and as a result you and all your loved ones took a graphics hit moving from Tiger to Leopard. Many argue the hit is minimal, and Leopard has so much more software and hardware compatibility that is more than worth it, a sentiment to which I firmly adhere. I do miss Classic, but otherwise Leopard...rocks. On x86 Linux I got used to doing all kinds of tweaks to get better video performance out of older machines, and one of the main ways was to set the v-sync to blank. Usually this was achieved by clicking a box deep within the bowels of compiz or editing a metacity preference file in nano. I'm no expert, but on LCD monitors I've read the benefits afforded by v-sync are pretty much a non issue. Lets face it, not many people are sitting in front of CRT's in 2013. If I've just deeply insulted Al in Syracuse, who is still in love with his 21inch ViewSonic purchased for $1500 (no, for real) from MacMall back in 1997, I apologize.

Honestly I never knew this tweak was possible in OS X. I thought Apple just locked all of that graphics stuff down tight to keep it away from those pesky end users. Then I stumbled upon a youtube video from a fellow PowerPC enthusiast, which sadly now seems to have been taken down or I'd post a link to it for reference. He had a bunch of good tips for improving graphics performance, most of which are well known, like using a 2-D instead of a 3-D dock, etc, etc. I was just about to stop watching when he showed viewers how to disable v-sync, and that caught my attention.

In order to perform this maneuver safely you'll need to have Xcode installed. If you don't have it its a free download from Apple, you will have to register as a developer and then sign over your first born child for ritual sacrifice, but once that's done its just a 300 MB download. You'll need an older version of Xcode, 3.3.1, as the newer ones are naturally Intel only. It is possible to do this in Text Edit, but personally I lack the intestinal fortitude to do so, see..I once hosed a Panther install fiddling around with a preference file in Text Edit. Xcode makes this simple, and for reasons probably only in my head it feels much safer.

What you want to do is go to your Hard Drive and open up the Library folder, then the Preferences folder. What you are looking for is com.apple.windowserver.plist, right click on that file, if you have Xcode you'll have the Property List Editor as an option, and open it with that. Now under Compositor look for "deferred updates" and set that to zero. Congratulations, you have just set your v-sync to blank on 10.5. There are some other settings which some turn off in there relating to Quartz Extreme and OpenGL but personally, I left those well enough alone.

Now anytime one fools around with system files, especially com.apple.plist's, bad things can happen. So, readers beware, and exercise all due caution. I followed the above steps and nothing bad happened, and, upon reboot I noted some definite improvements in overall window snappiness (such a technical term). Dock minimizations, even the hated "genie" effect were now lightning quick. The vicious tear I had passing my cursor over the dock in 3-D mode was also gone. Personally I use the 2-D dock so it wasn't a huge win for me, but overall this was a satisfying tweak.

On PowerPC OS X in 2013 its all about them little victories.