Mac Pro

The Mac Pro is an Intel Xeon-based workstation computer manufactured by Apple Inc. The Mac Pro, in most configurations, is the fastest computer that Apple offers, and is one of three desktop computers in the current Macintosh lineup, the other two being the iMac and Mac Mini. The machine is also the basis for the Mac Pro Server, which bundles the Mac Pro hardware with Mac OS X Server as a replacement for the Xserve line of servers.

Outwardly, the Mac Pro resembles the last version of the Power Mac G5, and has similar expansion capabilities. An Intel-based replacement for those machines had been expected for some time before the Pro was formally announced on August 7, 2006 at the annual Apple Worldwide Developer's Conference. The first Mac Pro was based on dual Dual-core Xeon Woodcrest processors. This was replaced by a dual Quad-core Xeon Clovertown model on April 4, 2007, and again on January 8, 2008 by a dual Quad-core Xeon Harpertown model.

The current model Mac Pro was announced on July 27, 2010 and features Intel Xeon processors based on the Nehalem/Westmere architectures. A "speed bumped" version was released in 2012. These systems offer options of up to 12 processing cores, up to four optional 2TB hard disk drives/512GB solid state drives and ATI Radeon HD 5770/5870 graphics.

The original 2006 Mac Pro and its 2007 update are not officially supported to run OS X Mountain Lion, which will only run on 2008 and newer Mac Pros. However, people have had success booting Mountain Lion on early Mac Pros using newer video cards and the Chameleon bootloader.

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. As such, the name "Mac Pro" was widely used before the machine was announced.

The Mac Pro is a workstation similar to other Unix workstations such as those previously manufactured by 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, 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 two dual-core processors, but lacked the storage expansion capabilities of the newer design.

In general, the Mac Pro has been well received in the press. The combination of high performance, reasonable expandability, very quiet operation and the quality of its 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 prices that are considered quite competitive, even by reviewers who do not normally review Apple systems.

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$2299, much more comparable with the former base-model dual-core G5 at US$1999, although offering considerably more processing power. Post revision, the default configurations for the Mac Pro includes one quad-core Xeon 3500 at 2.66 GHz or two quad-core Xeon 5500s at 2.26 GHz each.

Like its predecessor, the Power Mac G5, the Mac Pro is Apple's only desktop with standard expansion slots for graphics adapters and other expansion cards.

Description

 * The specifications below are from Apple's "tech specs" page or developer notes, except where noted.

Processors
The current Mac Pro is available with one or two processors with options giving four, eight, or twelve cores. As an example the eight core standard configuration Mac Pro uses two Quad core x8 Intel E5620007 Xeon processors @2.4 GHz, but can be configured with two Hexacore Core Intel Xeon Processor X5670 @2.93 GHz. All current Mac Pros have processors supporting Hyper-Threading which allows two threads to run on each core. The four core versions come with 8MB of Intel Smart cache (L3 cache) while all others come with 12MB for each processor. All current Mac Pro processors are capable of Intel's Turbo Boost technology, which dynamically boosts the clock rate of a core in intervals of 133 MHz if the CPU temperature is below average conditions.

Memory
The original Mac Pro's main memory used 667 MHz DDR2 ECC FB-DIMMs; the early 2008 model used 800 MHz ECC DDR2 FB-DIMMS, the current Mac Pro uses 1066 MHz DDR3 ECC DIMMs for the standard models, and 1333 MHz DDR3 ECC DIMMs for systems configured with a 2.66 GHz or faster processors. In the original and 2008 models, 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 × 4 GB) to be installed. 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. 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, for pre-2008 Mac Pro models 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. (see notes below). Mac Pro computers made in 2009 and later do not require memory modules with heatsinks.

Hard drives
The Mac Pro has room for four internal 3.5" SATA-300 hard drives in 4 internal "bays". The hard drives are mounted on individual trays (also known as 'sleds') within the bays by captive thumbscrews similar to the ones used for the PCIe expansion slots. A set of four drive trays is supplied with each machine. Adding hard drives to the system does not require cables to be attached as the drive is connected to the system simply by inserting it in the corresponding drive slot. A case lock on the back of the system locks the disks trays into their positions.

The Mac Pro also supports Serial ATA solid-state drives (SSD) in the 4 hard drive bays via an SSD-to-hard drive sled adapter (mid-2010 models and later), and via 3rd-party solutions for earlier models (e.g., via an adapter/bracket which plugs into an unused PCIe slot). Various 2.5-inch SSD drive capacities and configurations are available as an option on new machines.

The Mac Pro is also available with an optional hardware RAID card. With the addition of a SAS controller card or SAS RAID controller card, SAS drives can be directly connected to the system's SATA ports.

Two optical drive bays are provided, each with a corresponding SATA-300 port and an ATA-100 port. Many optical drives require the older style ATA ports, including those currently shipped with new machines.

The Mac Pro has one P-ATA port and can support two P-ATA devices. It has a total of six SATA ports – four are connected to the system's drive bays, and two are not connected. These extra SATA ports can be put into service through the use of after-market extender cables to connect internal Optical drives, or to provide eSATA ports with the use of an eSATA bulkhead connector. However, the two extra SATA ports are currently unsupported and disabled under Boot Camp.

At the current time, a built to order Mac Pro can be configured with up to 8 TB of storage (4 × 2TB disks) or 2 TB (512 x4 SSD).

Expansion cards
For internal expansion the current Mac Pro has four PCI Express (PCIe) 2.0 expansion slots. The 2008 model had 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 double wide and intended to hold the main video card, arranged with an empty area the width of a normal card beside it 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 ATI CrossFire, limiting its ability to use the latest "high-end gaming" video card products; however, individuals have reported success with both CrossFire and SLI installations when running Windows XP, as SLI and CrossFire compatibility is largely a function of software.

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

External connectivity
For external connectivity, the Mac Pro includes five USB 2.0 and four FireWire 800 ports. Networking is supported with two built-in Gigabit Ethernet ports, while 802.11 a/b/g/n Wi-Fi support (AirPort Extreme) is built in. Bluetooth required an optional module in the Mid 2006 model, but is standard in the Early 2008 and newer models. Displays are supported by one or (optionally) more PCIe graphics cards. Each card has two Mini DisplayPort connectors and one dual-link Digital Visual Interface (DVI) port, with various configurations of on-card graphics memory available.

Digital (TOSlink optical) audio and analog 1/8" stereo mini jacks for sound in and out are included, latter becoming available on both the front and back of the case.

Unlike other Mac computers, the Mac Pro does not include an infrared receiver (required to use the Apple Remote). Beginning with Mac OS X Leopard, Front Row can be accessed on the Mac Pro (and other Macs) using the Command (⌘)-Escape keystroke.

Case


The exterior of the aluminum case is very 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 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 much noisier Power Mac G5, and proved difficult to measure using common sound pressure level meters.

Mac Pro Server
On November 5, 2010, Apple introduced the Mac Pro Server, which officially replaces the Xserve line of Apple servers as of January 31, 2011. The Mac Pro Server comes with an unlimited Mac OS X Server license and an Intel 2.8 GHz Quad-Core processor, with 8GB of DDR3 RAM.

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 BIOS backwards compatibility, allowing dual and triple boot configurations. These operating systems are installable on Intel x86 based Apple computers:


 * 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 Apple has provided on top of EFI. Installing any additional operating system other than Windows is not supported by Apple, because the Boot Camp drivers are Windows only. It is often possible to achieve full or nearly full compatibility with another OS by using 3rd-party 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 the 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 is that a maximum of 4 partitions can be made on any such hard drive (including the EFI partition). This is because logical and extended MBR partitions are not possible which means that more than 4 partitions cannot be referenced for the MBR component of the configuration. Thus, having more partitions would force MBR and GPT to have differing partitioning schemes. The Disk Utility command-line application in Mac OS X (in addition to numerous 3rd-party graphical packages) can nondestructively resize a single partitioned HFS+ formatted volume to a scheme usable for dual/triple boot configurations with BIOS/MBR.

Add-on hardware compatibility

 * For 2006 and 2008 models, 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. Several third-party, self-installable memory upgrades that include Apple-specified heat sinks are available. In contrast, the 2009 Mac Pro with Nehalem processors uses unbuffered memory with no heatsinks.


 * The Mac Pro, as with other Mac platforms, requires Mac OS X firmware. That is to say, a PCIe video card designed exclusively for other operating systems will not work properly under Mac OS X without appropriate drivers and/or firmware; however, they will work under the operating systems they were designed for, if installed via Boot Camp or other means. Some video cards and other hardware accessories not marketed for Macs can nonetheless be tricked into compatibility through flashing drivers from either similar Mac hardware or with a custom firmware onto non-supported hardware. Also, AMD released the ATI Radeon HD 3870, which is compatible with both Mac Pros and PCs from other manufacturers. The Radeon HD 6XXX series of Graphics Processors (excluding 69XX), also released by AMD in 2010, will work without being flashed under Mac OS X if the user has installed drivers from Mac OS X Lion.


 * Displaying video while booting Mac OS X requires a GPU with hardware that conforms to the UEFI specification (referred to as EFI) in order to display the 32-bit color video output of the Mac bootloader. Using a modified card without EFI-capable firmware, video data will not be displayed while booting Mac OS X, but video will be displayed after the operating system has loaded the display drivers. As of 2011, the firmware on the majority of so-called PC-only video cards do not support EFI. However, firmware can be dumped from the ROM of an EFI-compatible card, such as the AMD's Mac Radeon HD 4870, and then flashed onto the ROM of an otherwise matching non-EFI PC video card. Unfortunately, the ROM in most graphics cards only hold 64k of data, whereas EFI-compatible cards require 128k. Dumped ROM images can be trimmed down, creating a custom firmware to fit onto the ROM of a non-efi card.