After change the original disk by a WD Mainstream Classique 2 Tb the performance have fallen. OS: Windows 7. BIOS configuration ACHI. On Windows CACHE is enabled. The problem is a a very slow transfer rates. Please Help!
As a recommendation, test the drive using the Windows DLG utility to make sure that is not a drive issue.
For information on how to test the drive, please see the link below.
Also check that the drivers for the SATA ports are properly installed.