Mac Pro

Developer	Apple Inc.
Type	Workstation
Release date	August 7, 2006
Introductory price	USD$2,299 (standard configuration US$2,799)
CPU	Intel Xeon, 1 × quad-core 2.8 GHz 64-bit 2 × quad-core 2.8, 3.0, or 3.2 GHz 64-bit
Website	www.apple.com/macpro/

The Mac Pro is a workstation computer manufactured by Apple Inc. The machines are based on an Intel 5400 chipset (with PCI Express architecture) and Xeon microprocessors, but are similar to the Power Mac G5 they replaced in terms of outward appearance and expansion capabilities. They are currently the most powerful desktop computers in the Macintosh lineup.

The Mac Pro was formally announced on August 7, 2006 at WWDC.^[1] Along with the Mac Pro, a new Xeon-based Xserve was also announced, completing Apple's transition from the PowerPC to x86 architecture. On January 8, 2008 Apple unveiled the first 3.2 GHz, 8-core Intel Xeon (Harpertown 45nm) -based Mac Pro.^[2]

Overview

An Intel-based replacement for the Power Mac G5 had long been expected prior to the release of the Mac Pro. The iMac, Mac mini, MacBook and MacBook Pro had moved to an Intel-based architecture starting in January 2006, leaving the Power Mac G5 as the only machine in the Mac lineup still based on the PowerPC. Speculation about the G5's eventual replacement was common. Rumors initially expected the machine to differ physically from the existing G5 and considered a number of different possible internal configurations based on different chipsets. But the coincidence of Intel releasing a new Core 2-based Xeon workstation platform just prior to the 2006 Worldwide Developers Conference (WWDC) made it fairly obvious that the resulting machine would be based on it. Even the naming was "obvious"; Apple had dropped the term "Power" from the other machines in their lineup, and started using "Pro" on their higher-end laptop offerings, the name "Mac Pro" was widely used before the machine was announced.^[3]

The Mac Pro is a high-end computer, similar to the most powerful Unix workstations from vendors such as SGI or Sun Microsystems. Although the high-end technical market has not traditionally been an area of strength for Apple, the company has been positioning itself as a leader in non-linear digital editing for high-definition video,^[4] which demands storage and memory far in excess of a general desktop machine. Additionally, the codecs used in these applications are generally processor intensive and highly threadable, speeding up almost linearly with additional processor cores. Apple's previous machine aimed at this market, the Power Mac G5, had up to four processors, but lacked the storage expansion capabilities of the newer design. In order to serve this market, Apple sells a variety of standardized bundles combining a Mac Pro with fairly high-end components; for instance, all available setups can support the 30" Cinema Display.

In general, the Mac Pro has been well received in the press.^[5] The combination of high performance, reasonable expandability, very quiet operation and superb mechanical design makes it routinely appear as the comparison system against which other systems are measured. The Xeon platform is, however, Intel's "high end" system and not aimed at more general purpose use. Nevertheless, current-generation Xeons are priced competitively with their high-end desktop platforms, allowing Apple to sell a very powerful system at price points that are considered quite competitive, even by reviewers that do not normally review Apple systems.^[6]

Original marketing materials for the Mac Pro generally referred to the middle-of-the-line model with 2 × dual-core 2.66 GHz processors. Previously, Apple featured the base model with the words "starting at" or "from" when describing the pricing, but the online Apple Store listed the "Mac Pro at $2499", the price for the mid-range model. The base model could be configured at US$2200, much more comparable with the former base-model dual-core G5 at US$1999, although offering considerably more processing power. Post revision, the default configuration for the Mac Pro includes two quad-core 2.8 GHz Xeon "Harpertown" processors.

There is a fairly large performance gap between the Mac Pro and Apple's most powerful consumer machine, the iMac. A particular sore point for many is that the Mac Pro is the only machine in Apple's lineup that allows the end user to easily change the graphics card among other things. Other machines in the lineup use integrated graphics or hard-to-replace expansion cards and higher cost laptop parts, while the Mac Pro uses the industry standard PCIe slots. The iMac series use graphics cards and processors that are technically replaceable by a user, though the case design restricts access. Buying a workstation platform just to allow for upgradable graphics is something many people and reviewers have complained about. This has led to calls for a smaller, mid range machine with more limited expansion capabilities but retaining additional PCIe slots.^[7]

Description

The specifications below are from Apple's "tech specs" page^[8] or developer notes^[9], except where noted.

Processors

The Mac Pro uses either one or two Xeon 5400 "Harpertown" 64-bit CPUs for a total of four or eight processor cores. Each CPU chip has 12 MB on-chip cache shared among its processor cores.^[10] Each processor slot has its own independent 64-bit 1600 MHz front side bus, offering an aggregate throughput between the CPUs and the "northbridge" of 21.3 GB/s.^[11]

The Mac Pro (Early 2008 model, and possibly others) is currently (April 2008) unsuitable for virtualization applications, because Intel Hardware Virtualization is switched off in the bios, with no way of enabling it. A similar bug in the Mac Mini was later fixed via a firmware update.^{[citation needed]}

Memory

The original Mac Pro's main memory used 667 MHz FB-DIMMs; its successor uses 800 MHz FB-DIMMs. These modules are installed in pairs, one each on two riser cards. The cards have 4 DIMM slots each, allowing a total of 32 GB of memory (8 x 4 GB) to be installed ^[12]. Notably, due to its FB-DIMM architecture, installing more RAM in the Mac Pro will improve its memory bandwidth, but may also increase its memory latency.^[13] With a simple install of a single FB-DIMM the peak bandwidth is 8 GB/s, but this can increase to 16 GB/s by installing two FB-DIMMs, one on each of the two buses, which is the default configuration from Apple. While electrically the FB-Dimms are standard, Apple requests that users use larger-than-normal heatsinks on the memory modules that they install. Problems have been reported by users who have used third party RAM that had normal sized FB-Dimm heatsinks.^[14](see notes below).

Hard drives

The Mac Pro has room for four internal hard drives, each with its own SATA-300 port. The hard drives are mounted on individual trays, provided with the machine, by captive thumbscrews similar to the one used for the PCIe slots. There are no cables to be attached, the SATA and power connectors are firmly attached to the case, and the drive is connected to them simply by pushing it in. The case lock on the back of the machine locks the trays into position. The Mac Pro now offers hardware RAID circuitry^[15]. Two optical drive bays are available, each with a SATA-300 port and an ATA-100 port. Many optical drives still use the older ATA ports, including those currently being shipped with the machines. The Mac Pro also has two internal SATA ports that are not connected to drive bays; these can be put into service through the use of after-market extender cables.^[16]

Expansion cards

For internal expansion the Mac Pro has two PCI Express (PCIe) 2.0 expansion slots and two PCI Express 1.1 slots, providing them with up to 300 W of power in total. The first slot is intended to hold the main video card, and is arranged with an empty area the width of a normal card beside it in order to leave room for the large coolers modern cards often use. In most machines, one slot would be blocked by the cooler. Instead of the tiny screws typically used to fasten the cards to the case, in the Mac Pro a single "bar" holds the cards in place, which is itself held in place by two "captive" thumbscrews that can be loosened by hand without tools and will not fall out of the case.

The PCIe slots can be configured individually to give more bandwidth to devices that require it, with a total of 40 "lanes", or 13 GB/s total throughput. When running Mac OS X, the Mac Pro currently does not support SLI or CrossFire, limiting its ability to use the latest "high-end gaming" video card products; however, individuals have reported success with SLI installations when running Windows XP.^[17]

The bandwidth allocation of the PCIe slots can be configured via the Expansion Slot Utility included with OS X only on the August 2006 Mac Pro. The Mac Pro (Early 2008) has its slots hardwired as follows.

	Default
Slot 4	4x
Slot 3	4x
Slot 2	16x
Slot 1 (Double-Wide)	16x

External connectivity

For external connectivity the system includes five USB 2.0 and four FireWire ports, two of the latter being FireWire 800. Networking is supported with two built-in Gigabit Ethernet ports, while 802.11 a/b/g/draft-n^[18] Wi-Fi is supported via an optional AirPort Extreme card. Bluetooth is now standard. Unlike other recent Mac products, the Mac Pro does not include the infrared receiver needed to use the Apple Remote. However, Front Row is available on all Mac Pros running Mac OS 10.5 (Leopard) or later, and is accessible using the normal ⌘-Esc key combination. The system also provides both optical and electrical "headphone jacks" for sound in and out, the latter available on both the front and back of the case.

Case

The exterior of the aluminum case is similar to that of the Power Mac G5, with the exception of an additional optical drive bay, and a new arrangement of I/O ports on both the front and the back. The case is somewhat larger than a typical PC of the same generation, at 20 × 18½ × 8 inches, compared to a typical desktop PC (the Dell Dimension 9100) at 17½ × 17½ × 6½ inches. Some of the difference in height is due to the "handles" on the top and bottom of the case. The case can be opened by operating a single lever on the back, which unlocks 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 can be accessed with the one panel removed, and require no tools for installation.

The Xeon processors generate much less heat than the previous dual-core G5s, so the size of the internal cooling devices has been reduced significantly. This allowed the interior to be re-arranged, leaving more room at the top of the case and thereby allowing the drives to double in number. Less heat also means less air to move out of the case for cooling during normal operations; the Mac Pro is very quiet in normal operation, quieter than the already-quiet Power Mac G5^{[19] [20]} , and proved difficult to measure using common decibel meters.^[21]

Specifications

• Processors: One (2.8 GHz) or two (2.8, 3.0, or 3.2 GHz) Quad-core Xeon 5400 ("Harpertown" Core microarchitecture) processors.
• Memory:^[10] Standard 2 GB 800 MHz DDR2 fully-buffered ECC RAM (upgradeable to 32 GB), in eight FB-DIMM slots
• Graphics:^[10] bytes, i.e., 1 gibibyte</ref> ATI Radeon 2600 XT 256 MB, nVidia 8800 GT 512 MB or an nVidia Quadro FX 5600 1.5 GB
• Storage:^[22] Four drive bays for Serial ATA (500 GB, 750 GB, 1 TB) or SAS (300 GB) hard disks: included disks have 16 MB cache (32 MB on the 1 TB hard drive) and run at 7200 RPM (15,000 RPM for the SAS drives.) Maximum Supported: 4 TB SATA, or 1.2 TB SAS). Optional hardware RAID card available with 256 MB of battery-backed cache that allows for RAID levels 0, 1, and 5. SAS drives only available when using the hardware RAID card.
• Optical Drive: 16× SuperDrive (multiple DVD write formats) (Pioneer DVR-111D or Sony DW-D150A), optional second drive. Optical bays support ATA/100 and SATA.^[9]
• Networking: two Gigabit Ethernet ports, Bluetooth 2.0 built-in, optional AirPort Extreme 802.11 a/b/g/n
• I/O: five USB 2.0 (two on front), two FireWire 400 (one on front), two FireWire 800 (one on front), optical audio input and output, 3.5 mm stereo audio input and output (one output on front)
• Software: Mac OS X v10.5 Leopard, iLife '08, Comic Life, OmniOutliner, various trial software.

Operating systems

The Mac Pro comes with the BIOS successor EFI 1.1 and handles booting differently from the conventional BIOS-based PC.

Apple's Boot Camp provides backwards-BIOS-compatibility, and dual and triple boot configurations can be achieved.^[23] These operating systems are easily installable on Intel x86 based Apple computers:

• Mac OS X 10.5.0 and later (native, OS supports EFI)
• Microsoft Windows XP and Vista 32-bit & 64-bit (hardware drivers are included in Boot Camp) (only supports BIOS)
• Linux (most late 2006 or 2007 distributions) (supports both BIOS and EFI)

Other x86 operating systems such as x86 Solaris, DOS, BeOS, and BSD (which is very closely related to OS X) should also be easily installable. This is made possible by the presence of an x86 Intel architecture as provided by the CPU and the BIOS emulation Apple has provided on top of EFI. Note that installing anything other than Windows is not supported by Apple, and can cause driver problems because the Boot Camp drivers are Windows only. However, it is possible to achieve full or nearly full compatibility on some Linux distributions by using restricted drivers.

There are a number of challenges that one must face when trying to establish a multi-booting configuration on a single hard drive that uses the new GPT partitioning standard that Mac OS takes advantage of at the same time as MBR, which is commonly used by Windows and Linux (though Linux can use GPT). One must synchronize their GPT and MBR partition tables multiple times during the setup of such configurations. The key challenge being that a maximum of 4 partitions can be made on any such hard drive (including the EFI partition). This is because logical & extended MBR partitions are not possible which means that more than 4 partitions can not be referenced for the MBR component of the configuration. Thus having more partitions would force MBR and GPT to have differing partitioning schemes. The diskutil command-line app in Mac OS X can non-destructively resize a single partitioned HFS+ formatted volume to a scheme usable for dual/triple boot configurations with BIOS/MBR.

Compatibility

Software

• Software (PPC Emulation) - PPC-Native Applications: Note that many high-end PPC-native applications will need to be modified specifically to take advantage of the new Intel-based processor architecture in order to maximize on the Mac Pro's processor strengths, and PPC-native applications (such as Adobe Photoshop CS2 and earlier) may successfully run through translation software called Rosetta, which adds overhead and reduces actual software execution speed for those applications as it translates PPC-native instructions to Intel-native code. Speeds for some of these PPC-native applications may be lower on the Mac Pro than on the G5 models it replaces, and Rosetta does not support G5-processor-specific emulation.

• Software (Classic Emulation) - Classic (Mac OS 9.x and earlier): Intel-based Macs do not support Classic software, although third-party emulators such as SheepShaver may allow these applications to run.

• OS Minimums - The lowest version of the operating system that will support the Mac Pro is Mac OS X version 10.4.7. Earlier versions will not boot the computer.

Hardware

• PCI-Express slots are not backwards compatible with prior versions of PCI hardware, such as PCI/33, PCI/66 or PCI-X. The PCIe 2.0 slots on the January 2008 Mac Pro are backwards compatible with PCIe 1.1 hardware.

• Apple recommends an Apple-specified heat sink on each memory DIMM for cooling, and the required on-chip thermal manager may shut down memory, or increase fan speed, if it starts to overheat.^[14] Several third-party, self-installable memory upgrades that include Apple-specified heat sinks are available.

• The Mac Pro, as with other upgradeable Macintoshes in the past, requires custom video cards to work under OS X. That is to say, an off-the-shelf PCIe video card will not work in EFI or under OS X, however, they may work under other operating systems installed via Boot Camp or other means. There have been several attempts, with varying success, in creating drivers for them (a result of the OSx86 Project).

References

External links

• Apple's Mac Pro website
• Close-up pictures of the Mac Pro
• Review of the Mac Pro
• A Mac Pro with two 3.0GHz quad-core Intel Xeon processors