Hi, just got me a new computer and tried to activate AHCI. I'm not sure if it worked. Motherboard: Asus P5K-V Hard drive: WD2500KS-00MJB0, 16 MB buffer Windows XP Pro SP2 64 bits version (yes, I have used Intel Storage Manager 64 bits, too) CPU: Intel Core 2 Quad Core Q6600 RAM: 2 Gb DDR2 dual channel @ 800 MHz Everything works fine, no BSOD. BUT: - Roadkil's Disk Speed (roadkil.net/DskSpeed.html) gives me the exact same figures as before. The speed is actually lower than my older system (AMD XP 2600+ Athlon, Seagate 250 Gb). The speed has dropped from 65 Mb/sec to 61 Mb/sec, overall score from 8042 to 6789. - I get ALL these things in the Device manager (see below) - I have copied stuff from my old hard drive. Top speed: 57 Mb/sec . But, after going over 20-25 Mb/sec, everyting else just freezes. All other programs almost stop working (tv tuner winfast pvr2, yahoo messenger, notepad, total commander, opera browser). Also, copied from one partition to other, both on this new drive, same thing happens, everything else freezes after 20-30 Mb/sec. I've got the same poor result before and after activating AHCI. In the BIOS, I have activated these settings: - SATA Configuration - Enhanced (before - same Enhanced option was enabled) - JMicron 3SATA/PATA controller - Enabled (before - same Enhanced option was enabled) - Controller Mode - AHCI (before it was IDE, other option is RAID) What could be wrong. Is that hard drive so poor? Thanks!