Apple upgraded the Mac Pro in 2010 with Westmere Xeon CPUs, including a dual six-core option that can power through multithreaded workflows with aplomb. But what if you don't want to shell out all that money for a new Mac Pro? A clever hacker has discovered a firmware hack to effectively transform 2009 vintage Mac Pros into 2010 Mac Pros, including compatibility with Westmere CPUs, faster RAM, and audio output via Mini DisplayPorts.

A member of the forums on netkas.org—where lots of hackintoshers and system tweakers exchange tips—discovered the mechanism Apple uses to install EFI firmware updates. By exploiting that mechanism, a user named "MacEFIRom" was able to develop scripts to force older, 2009 Mac Pros to accept a firmware update intended for the 2010 Mac Pros. That firmware enables a 2009 Mac Pro to act and operate just like the 2010 Mac Pro.

The firmware enables three main features for 2009 Mac Pro users. Perhaps of primary interest is that users will be able to install 32nm Westmere Xeons, including six-core variants used in the high-end 2010 Mac Pro, into their older machine. Single-socket machines can use W-series CPUs, while dual-socket machines will need dual-QPI enabled chips including the E5600 and X5600-series chips. (A source who applied the firmware update told Ars that Westmere CPUs are identified with "B1" stepping in the identification code.)

Even if you didn't plan to upgrade the CPU, though, there are other benefits. Some Nehalem CPUs can support 1333MHz DRAM speeds, but are limited to 1066MHz on the older Mac Pros. The firmware update will enable the full 1333MHz speed if you have a CPU and RAM combo that can support it. And, the updated firmware will channel audio signals through the Mini DisplayPorts on installed GPUs, making it easier to use with HDMI displays.

The firmware trick works because Nehalem and Westmere Xeons use same chipsets and sockets. As we noted in our review of the dodeca-core 2010 Mac Pro, the internals are no different form that of the octo-core 2009 Mac Pro we reviewed in 2009. Apple seems to have merely tweaked the firmware and offered new CPU options for 2010.

While several users have applied the firmware hack with success, there are a few caveats to note if you plan to do it yourself. Apple does not consider the CPU in any of its machines to be a user-serviceable part; swapping it will void AppleCare, and so will applying an unsupported firmware update. The tool that MacEFIRom released allows users to revert an upgraded 2009 Mac Pro to the original firmware, so it's possible to undo the hack before taking it in for service. However, some refurbished 2009 Mac Pros have a special firmware revision that is not publicly available—if you have one of these machines, you won't be able to revert back to stock.

Also, since your 2009 Mac Pro thinks it is a 2010 Mac Pro (it will report itself as a MacPro5,1 in System Profiler), your original system install discs will no longer work. You'll need 2010 Mac Pro restore discs if something catastrophic happens and you need to reinstall Mac OS X.

Finally, newer Mac Pros have a newer version of the System Management Control firmware. The SMC controls (among other things) the cooling fans, and the newer version in 2010 Mac Pros can make some GPUs run cooler. However, the older firmware for the 2009 Mac Pros doesn't appear to adversely affect the operation of the machine in any way.