Back on Friday we published Mac OS X 10.6 benchmarks and found it to offer some terrific performance improvements, but at the same time, there were a few notable regressions. Apple engineers have been working hard at pushing technologies like Grand Central Dispatch (GCD), OpenCL, full 64-bit support, and other changes to their OS X stack to bolster its performance capabilities and reduce the overall footprint. Now that we have tested Mac OS X 10.6, we are seeing how its performance compares to that of Ubuntu Linux. Ubuntu 9.10 "Karmic Koala" will be out in October and does have some performance improvements as our earlier tests have shown, but Canonical engineers have not been exclusively focusing on performance optimizations with this release. Can the Karmic Koala outperform Snow Leopard? Yes and no.