Recently I change my BIOS SATA mode on IBM server for a reason, usually I use native and now I change it to compatible. The server running dual operating system, Windows 7 and Linux. On Windows 7 , I am not found any performance change , the server serve well.

When I try using Linux (CentOS) the performance change happen. I feel the web server is very slow even only accessed by few client. Actually , I didn’t feel any performance change after I use the server for testing. I use the server for local quiz with moodle , with 200 multiple choice question and 70 terminal┬ásimultaneously access it the server just near died :))

Debug the server , when I run “df -h” ┬ácommand , I found something strange , the hard disk detected as “hda” , as I remember the hard disk is SATA , and hdd is usually for ATA harddisk. I change the BIOS SATA mode to native and test it. I am run “df -h” command again and the hard disk now detected as “sda”. Curious about the speed deference of “hda” and “sda” , I did hard disk speed test with “hdparam” command and here the result :

And I know where is the problem :) the speed deference is huge