An update for the Msahci.sys driver has been released for AMD chipsets
This article discusses an update for the Microsoft Advanced Host Controller Interface (AHCI) driver, Msahci.sys. This driver was specifically built for the Serial Advanced Technology Attachment (SATA) mode of a disk device. The update changes the Msahci.sys driver so that the driver does not call RecordExecutionHistory(), which is called at various times, such as after each command execution. This function copies the AHCI registers into an execution history buffer for debugging. This copy activity can decrease the performance of AMD-based CPU chipsets because Msahci.sys logs entries every time that it is executed.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB974073.