For some users, Windows 7 upgrade could take 20 hours

Tests conducted by Microsoft show that upgrades from Windows Vista to Windows 7 will be about 5 percent faster than other upgrades involving Vista. But in certain situations, “faster” could mean more than 20 hours.

In a blog post Sept. 11, Chris Hernandez, who works with the Windows 7 deployment team, wrote that the team had tested in-place upgrades from Vista to Windows 7 for a variety of user profiles – from “medium users” running low-end hardware to “super users” running high-end hardware. The team also tested the times for a variety of clean installs, which is the path current users of XP would take. Hernandez also compared upgrade times for 32-bit and 64-bit versions.

The fastest time for an in-place upgrade from Vista Service Pack 1 – in which the user upgrades the operating system while keeping all data on the machine – was 84 minutes for a “medium user” with high-end hardware. The profile for a medium user included 70G of data and 20 installed applications.

The longest install involved a super user (650G of data, 40 apps installed) running midlevel hardware. That upgrade, for a 32-bit version, took 20 hours, 15 minutes.

Most scenarios, covering medium, heavy and super users each with low-, mid- and high-end hardware, fell in the middle – and closer to the faster time. They ranged from about 1 hour, 41 minutes to about 6 hours, 30 minutes (heavy user, low-end hardware). A couple of 64-bit upgrades involving super users took over 10 hours.

In every case, however, the upgrade times were faster than that of a comparable user upgrading from Vista SP 1 to a new version of Vista SP 1. In addition to installing more quickly, early tests have shown some performance improvements under Windows 7.

The natural upgrade path for Windows 7 is from Vista, so users of XP would have to wipe a PC’s hard drive clean, install the OS and then restore their applications and backed-up data. But at least the install times aren’t bad.

Clean install times ranged from just under 27 minutes (on fast-running, high-end hardware) to just under 47 minutes (low-end hardware, 64-bit version).