snydeq writes: When Randall Kennedy first performed his generational Windows multicore performance tests, Windows 7's quad-core advantage wasn't enough to allow Windows 7 to overtake the leaner, more efficient XP under heavy workloads. A year later, new benchmarks tell a different story, with Windows 7 blowing past XP, delivering results that are 47 to 178 percent faster and showing far superior scalability — by a factor of more than 3.5 — when moving from a single quad-core CPU to dual quad-core. 'Simply put, Windows 7 is significantly faster than Windows XP when running heavy, multitasking workloads on advanced, multicore hardware. And when considered in light of current trends in PC hardware design and multicore road maps, this advantage should be enough to sway even the most ardent fence sitters to finally jump on the Windows 7 bandwagon,' writes Kennedy, who provides extensive generational performance benchmarks, as well as a deeper look at his testing methodology. Some of this performance gain is due to NUMA and QPI advancements that have improved the Intel architecture, Kennedy admits, but 'to make the most of today's smarter CPUs, you need a smarter OS.'