because of their hard disk.
I don't know why. For the similar 5400RPM disk, HP 120GB (WDC brand, SATA150, 8MB cache) is way way slower than the disk on cheaper Toshiba (also 5400RPM, 8MB cache, 160GB).
The total benchmark score for Toshiba (around $520) is 490; HP ($800) is 500.
I will never buy another HP computer in my lifetime.