It's great news that Steam is now available on Mac, but some users have been upset that performance isn't quite as smooth as it is on PC. Maybe this latest update will help!
Since the service launched on Mac earlier this year, Valve has been working with Apple to "close the performance gap" between games on PC and those on Apple's computers. Today, a Mac OSX update coupled with some tweaks on Valve's end means that gap has been made a lot smaller.
Valve says performance on the following Macs are now enjoying framerate increases of between 15-120%:
iMac (Late 2009 and Mid 2010), Mac mini (Early 2009 and Mid 2010), Mac Pro (Early 2009), MacBook (Early 2009 and Mid 2010) and MacBook Pro (15-inch, Mid 2010) and MacBook Pro (17-inch, Mid 2010)
If your Mac isn't listed there? Older machines are SOL, as Valve reckon "we are generally already operating at the limits of the hardware, so it is not obvious that any significant performance improvements can be achieved in the future".
For a more technical breakdown of the improvements and tweaks made, head to Valve's site below.