for me it's like 20 seconds from the end of POST to the Windows login screen. After typing the password it take about 5-6 seconds to get to the desktop, although I think some things may still be loading even after I get control of the desktop. btw, I have raid-0 2x160GB 7200rpm sata drives (seagate). Linux take 45 seconds to load from end of POST to login screen (gdm), but it's installed on a single 160GB 7200rpm. But I have a lot of services in Linux, like NFS, Samba, VPN, SSH, MySQL, firewall and all the ususal linux daemons.