OS freezes at SATA-drive activity.

[Strong]

It's real nightmare in reaction speed while my hdd starts to work
(just simply doing a thing with swap file, for example) aboudantly! All
apps freeze! And it is on F8 with AMD Turion 64 x2!

So, if You have an answer to the following question(s), please give me
Your reply:

1. Why system freezes if, the SATA drive work is controlled by its one
hardware - namely controller, that since long time ago does all the
work for a drive thus unloading CPU, so why its work has enfluence on
whole the system?

2. What can I do stop such functionility? OR Minimize it at least?

Big thanks for Your replys. If important, the machine is laptop dell
inspiron 1501: AMD Turion 64x2 1,6 , ATI Radeon xPress200 , 512 RAM DDR
532 (functions at 226 MHz) , linux 2.6.23.9-85 .