xp is faster than vista only on low end pcs, on todays medium class pcs, vista outperforms xp in almost every expect(May it be in terms of speed, security, networking, etc, )….

xp takes a loong time to start from a cold boot but vista starts as if it was never turned off….
the secret lies in the fact that vista makes efficient use of the hardware present in the system provided that you should give it some good hardware platform to perform…….

seeing is believing, so better you try it yourself if you have a computer with some good configuration(dont forget to install 64-bit vista if your system supports as it provides much more speed than its 32-bit counterpart)