Apple offers an EFI firmware update for Mac Pro and Xserve 2009:
This update addresses the following issues for Mac Pro (Early 2009) computers:
Improves compatibility with virtualization products utilizing VT-d
Improves storage performance under Windows XP for Boot Camp users
Improves system reliability during the boot process
To complete the firmware update process, please follow the instructions in the updater application (/Applications/Utilities/MacPro EFI Firmware Update.app). The updater will launch automatically when the installation is complete.
For more information about firmware updates for Intel-based Macs, please visit: http://support.apple.com/kb/HT1557
