Google Chrome will thrash to disk a lot to disk, at least in version 0.2.149.27, build 1583 (the first publically available beta) in Windows XP. It is so bad that my entire computer locks up a bit and becomes unresponsive. Disabling phishing and malware protection seems to stop the thrashing:

Click on the monkey-wrench icon to the right of the address bar. Choose "Options" from the menu. Click the "Under the Hood" tab Disable the "Enable phishing and malware protection" check-box

[img_assist|nid=321|title=Google Chrome Disable Malware and Phishing Protection|desc=|link=none|align=none|width=418|height=315]