Valve has gotten a lot of press for porting its Steam client and games, starting with Portal, to Mac OS X. However, users of Apple computers might be getting the short end of the stick as far as performance and image quality go.
AnandTech came to those conclusions after testing the freshly released Mac version of Portal on a Hackintosh build with a Core i7-920 processor and a GeForce GTX 285 graphics card. The system had both OS X 10.6.3 and Windows 7 x64 installed.
At resolutions of 1280x800, 1920x1200, and 2560x1600, frame rates were reportedly 34 to 46% lower on the Mac compared to Windows. And looking at AnandTech's comparative screenshots, the Mac graphics are clearly lacking in contrast, with some highlights and effects missing entirely.
Perhaps those shortcomings can be blamed largely on Valve's brand-new OpenGL renderer for the Source engine. AnandTech, for its part, blames Apple's OpenGL implementation. Perhaps we should also note that the GeForce GTX 285 isn't exactly a staple of Apple's current lineup—a lone EVGA version of the card is available on the Apple store, but it doesn't come as an option for the Mac Pro.