Apple today released Mac Pro SMC Firmware Update 1.1 which adjusts fan behavior in the Mac Pro.
After this update has completed successfully, the Mac Pro’s SMC Version will be:
• 1.7f10 (Mac Pro)
• 1.5f3 (Mac Pro 8-core)
Mac Pro SMC Firmware Update 1.1 is available via Software Update and also as a standalone installer.
More info and download link (544KB) here.