You experience poor performance when a Windows Vista-based or Windows Server 2008-based computer accesses a solid state drive (SSD) disk that is installed on the computer
On a Windows Vista-based or Windows Server 2008-based computer, you have a solid state drive (SSD) that is installed on the computer. However, you may experience poor performance when the computer accesses the SSD disk.
This problem occurs if the computer uses the Microsoft AHCI driver (Msahci.sys). In this case, the Native Command Queuing (NCQ) feature is disabled for the SSD disk.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB9607350.