Apple also touts the 2013 Mac Pro’s energy use. We measured the power draw of this 8-core 2013 Mac Pro versus a 12-core 2012 Mac Pro. With its stock hard drive, the 2012 Mac Pro drew 257 watts at startup, 147W at idle, 220W at sustained load, and 256W at peak. We noticed that the processors were being underutilized in the 2012 Mac Pro, as the hard drive in the system was struggling to keep up. Switching over to an OWC 480GB Mercury Accelsior E2 PCIe SSD installed internally in the 2012 Mac Pro helped eliminate the storage bottleneck and allowed the processors to work harder, boosting the sustained draw to 260W and peaking at 320W. The new Mac Pro drew only 156W at startup, and just 58W at idle; however, it drew around 330W under sustained load, and 367W at peak.
GPUs vs. CPUs
Another area where the 2013 Mac Pro promises performance benefits—and an area our benchmarks may not fully recognize—is in GPU computing (aka, “GPU compute” or “general-purpose computing on GPUs”). Many things you do on a computer don’t require the full processing power of the GPU, which means that some of the GPU’s capabilities go unused. GPU computing allows applications, generally using OpenCL, to send discrete instructions and calculations to the computer’s GPU for processing. Given that today’s GPUs are extremely fast, use many cores, and offer substantial data throughput, they’re often able to process more—but smaller—bits of independent instructions, in parallel, than CPUs. (Engadget has a good primer on the topic.)
Apple has designed the Mac Pro with a heavy focus on GPU compute, and the fact that every configuration of the Mac Pro includes dual workstation-class GPUs means that developers can count on having substantial GPU resources available. In fact, the Mac Pro actually connects all displays to one GPU, leaving the second GPU available to focus exclusively on GPU-computing tasks. (This also means that the second GPU can power down when it’s not being used for such tasks.)
You can see the benefits of GPU computing in some of our benchmark tests: Version 10.1 of Final Cut Pro X includes updates specifically made to take advantage of the 2013 Mac Pro’s dual GPUs; and Mathematica is designed to benefit dramatically from GPU computing. Any app that uses OpenCL and OpenGL should immediately benefit from the Mac Pro’s improved GPU-compute performance, and we suspect that pro-level apps that don’t yet use OpenCL will be updated to do so, now that developers can depend on significant GPU-compute resources.
Upgradable inside, expandable outside
Easily the most controversial aspect of the new Mac Pro is what it doesn’t have: traditional internal expansion. You can upgrade the RAM to 64GB (that’s the official limit—I suspect that third-party vendors will eventually provide solutions for more); you can upgrade the built-in PCEe-based flash storage; and you can even replace the removable GPUs—assuming that, at some point down the road, Apple or a third-party vendor provides compatible GPUs that offer improved performance. And getting to those components is dead-simple: You just slide a small lock switch on the back panel of the computer, and then slide the Mac Pro’s aluminum shell up and off, revealing the components inside.
But once inside, you won’t find any PCI-card slots, empty hard-drive bays, or a place to add a new optical drive. (You don’t get an optical drive at all—this is 2013 Apple we’re talking about.) This is a dramatic change from the Mac towers of the past decade: The 2012 Mac Pro, for example, offered four hard-drive bays, two optical-drive bays, and four PCI Express slots; you could even add a RAID card to set up an internal RAID array.
Instead, you get the aforementioned external ports and connections, located on a panel in the rear. In a nice touch, that panel lights up whenever the computer is moved—Apple told us that many Mac Pro owners use their computers in dark studios, so the company added this feature to make it easier to see the panel. However, while Apple’s advertising shows how easy it is to rotate the Mac Pro to access the panel, in real-world use it’s not always such a seamless process: Unless all your cables are long enough (and flexible enough) to let you turn the computer around, you’re going to have to reach behind the computer (or unplug those cables first), just as you had to with an older Mac Pro.
This new approach will definitely present challenges—both logistical and financial—for some people. For starters, since the Mac Pro’s internal storage tops out at 1TB, many pros will need to spring for some external drives, or enclosures for existing drives. At the other extreme, some users will need to pony up for a Thunderbolt-based PCI expansion chassis to handle required PCI cards. (For those who used a PCI-card slot in an older Mac Pro for a workstation-class GPU, the new Mac Pro’s GPUs may make that particular card unnecessary.)
The good news is that Thunderbolt 2 should be adequate from a performance perspective for many such uses: Each Thunderbolt 2 port provides up to 20Gb/s of bandwidth to each connected device, and you can daisy-chain up to six devices on each port for a total of 36 external Thunderbolt peripherals (including displays). And USB 3.0 is a less expensive option for bulk storage where performance isn’t important.
The bad news, of course, is that such peripherals add to the cost of buying a new Mac Pro. But let’s be honest: Many of the people who really, truly need the Mac Pro and are willing and able to pay for it won’t hesitate too much to pay for the necessary accessories and add-ons. (Apple won’t come out and say that, but I’m sure more than a few people at the company have thought it.)
Still, while that may be true, the question some people are asking is “Why?” Why this dramatic change from what we’d come to expect from a “pro” computer? Apple’s take is that the new Mac Pro is looking forward, not back, by embracing current trends in computing: multiple processor cores, solid-state storage, GPU compute, external expansion that’s as fast as internal options, and so on. And this design reduces wasted space and resources.
The company has some valid points. For example, there are good reasons for separating storage and other expansion peripherals from the computer itself, including size, heat, and noise. Apple says that some of its pro users—for example, those working in recording and production studios—actually want to get hot, noisy components (such as hard drives and RAID arrays) away from the computer and the work area. Similarly, many pros use a SAN—often located in another room—for bulk data storage, and with older Mac Pros, this often required a fibre-channel card for connecting to the SAN. So even though your storage was elsewhere, you still had a big, loud, hot computer sitting next to you. Apple expects Thunderbolt 2 to handle such connections on the 2013 model, so your workspace contains only a small, quiet, and relatively cool-running computer.
How much of this is PR spin, and how much is Apple actually solving problems in new ways while embracing new technologies? I suppose it depends on how much you’ve got invested in “old” technologies and how much additional capital you’re going to have to expend to convert your work setup for full compatibility with the new Mac Pro. But I do think that once people get over the initial shock, many will be won over by the Mac Pro’s approach.
I say this in part because, despite the affection I still hold for my old Mac Pro with scads of drive space and upgrades, over the past week of using the new model, I came to appreciate many things about it: That it takes the same amount of space as one of my speakers. That I couldn’t hear it over the external hard drive under my desk. That after using it for an entire day, my office was no warmer. And that I could shut it down, unplug a few cables, pick it up with one hand, and take it to a different location. (Of course, this also raises questions about security—the machine doesn’t have any sort of lock or security slot.) Say what you will about the lack of internal expansion, there’s something pretty special about this design in many other respects.
All that said, few Thunderbolt peripherals are yet available, in part because this is the first Mac Pro to (finally) get Thunderbolt. I expect we’ll be seeing more PCI chassis, RAID configurations, stand-alone drives, and the like in the months to come. Macworld will be testing these peripherals as they become available, and we’ll be publishing a number of articles on the options for, and performance of, Thunderbolt gear for pros.
Three 4K (or pick six)
The new Mac Pro provides impressive display support. You can connect up to six non–4K DisplayPort displays, including any mix of Apple Thunderbolt Displays, Apple LED Cinema Displays, or third-party Mini DisplayPort displays. Alternatively, you can connect three massive 4K displays. Want to combine? The Mac Pro can handle, for example, one 4K display and four Mini DisplayPort displays. (The options differ slightly for Windows running via Boot Camp.) Apple says that for the best performance, if you have only two or three displays, you should connect each to a different Thunderbolt bus, and if you have more than three, you should never connect more than two to any single bus. (The top two Thunderbolt ports on the left are on one bus; the top two on the right are on another; and the bottom two, along with the HDMI port, are on the third.)
The Mac Pro also supports Display Port Multi-Stream Transport (MST), which allows multiple displays to be connected using a single connector or, in the case of some 4K displays, to use a single cable for a high-resolution display that previously required two DisplayPort connectors. (For those displays that still use two cables, the Mac Pro can automatically detect which cable contains the data for which half of the screen, assuming the display provides that information.)
For many years, “pro” meant a big, expandable tower case, lots of internal storage, replaceable graphics cards, and so on. For Apple, it now means “maximum performance when using pro apps.” In that respect, the new Mac Pro reflects multiple trends in computing. It, of course, continues Apple’s ongoing shift across its product lines towards flash storage and external expandability at the expense of capacious hard drives and internal upgrades. But it also illustrates the ways in which Apple and other vendors are responding, at the high end, to the fact that processor speeds simply aren’t increasing at the same rate that they used to: Namely, they are focusing on multi-core and GPU-based processing technology, in both hardware and software.
You can see this when you look at our initial benchmarks. A souped-up iMac has just as much horsepower as a new Mac Pro when it comes to many of the things nonprofessional users do on a daily basis. It’s not until you get to specialized applications that the Mac Pro really shines. Which means that this Mac Pro really is a Mac Pro: It’s a computer for professional users who need multiprocessing capabilities and the kind of high-bandwidth capability that only a high-end computer can provide. If you need this kind of performance, the new Mac Pro is for you.
Of course, some people won’t be happy with the new Mac Pro’s lack of internal expansion, and given the current paucity of Thunderbolt peripherals, and the limited number of apps that take full advantage of the Mac Pro’s capabilities, the new computer is in some ways ahead of its time. But if you want a Mac for professional work, you’ll have to accept these limitations—or keep using your older Mac Pro until more hardware and software is available. My guess is that most people who don’t jump ship—a threat heard frequently when the new Mac Pro was announced—will adapt fairly quickly. And as the computer finds its way into the hands, offices, and studios of pro users, we’ll see plenty of software updated for it, and hardware solutions for many of its current limitations, making the transition easier. (We plan to publish some of the real-world experiences of professional users, so you can see how these transitions are playing out.)
The big question for many pros will be which Mac Pro configuration to get. Since we haven’t been able to get our hands on any other Mac Pro models, we can’t yet make definitive recommendations about performance and value. However, based on what we’ve seen from our initial testing, and what we know about the various processors available, we can say that the more time you spend using multi-core-aware apps, the more you’ll benefit from more cores. Similarly, the more apps you use that take advantage of GPU computing, the more you’ll benefit from upgrading the Mac Pro’s GPUs to the D500 or D700. On the other hand, because the base clock speed goes down as the number of cores increases, you’ll get better overall single-core performance with fewer cores. Because every Mac Pro model is identical except for the options you choose, you can mix and match whatever components are the best fit for your apps and workflows.
Whatever configuration you create, one thing is certain: It won’t be like any “pro” Mac you’ve ever used before.
Updated on December 24, 2013 to fix minor error about which Thunderbolt ports share busses. Updated on January 5, 2014 to add a video.