and the back, and one less exhaust vent on the back. The case could be opened by operating a single lever on the back, which unlocked one of the two sides of the machine, as well as the drive bays. All of the expansion slots for memory, PCIe cards and drives could be accessed with the side panel removed and no tools were required for installation. The Mac Pro's Xeon processors generated much less heat than the previous 2-core G5s, so the size of the internal cooling devices were reduced significantly. This allowed the interior to be re-arranged, leaving more room at the top of the case and doubling the number of internal drive bays. This also allowed the elimination of the large clear plastic air deflector used as part of the cooling system in the Power Mac G5. Less heat also meant less air to move out of the case for cooling during normal operations; the Mac Pro was very quiet in normal operation, quieter than the much noisier Power Mac G5, and proved difficult to measure using common sound pressure level meters. The front of the case, which has small perforated holes across its entire surface area, has caused Macintosh enthusiasts to refer to the first generation as the "cheese grater" Mac Pro. Operating systems The Mac Pro comes with EFI 1.1, a successor to Apple's use of Open Firmware and the wider industry's use of BIOS. Apple's Boot Camp provides BIOS backwards compatibility, allowing dual and triple boot configurations. These operating systems are installable on Intel x86–based Apple computers: Mac OS X 10.4.7 and later Microsoft Windows XP, Vista, and Windows 7 32-bit & 64-bit (hardware drivers are included in Boot Camp) Other x86 operating systems such as Linux x86, Solaris, and BSD This is made possible by the presence of an x86 Intel architecture as provided by the CPU and the BIOS emulation which Apple has provided on top of EFI. Installing any additional operating system other than Windows is not supported directly by Apple. Though Apple's Boot Camp drivers are only for Windows, it is often possible to achieve full or nearly full compatibility with another OS by using third-party drivers. Specifications All are "obsolete." Reception Ars Technica reviewed the 2006 Mac Pro, calling it a solid "multiplatform device" and rating it 9 out of 10. CNET praised the design and value, although did not