Short Media threw 108 performance benchmarks at Windows XP Service Pack 1 and Windows XP Service Pack 2. The results:
The test PC equipped with Windows XP Professional Service Pack 1 was an average of 0.5% faster than the same hardware with Service Pack 2 installed. The percentage difference between faster and slower is insignificantly small. Less than 2 or 3 percent in some benchmarks could be dismissed by most but when gamers are looking to squeeze every extra frame out of their machines…it may count.