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REVIEW: Apple Mac Pro 2014

Posted on Jun 11, 2014 by Julian Mitchell

The three main number crunchers (the CPU and two GPUs), along with all the other bits that get hot, are bolted to a triangular heat sink, with a custom fan on the top pulling air up through it – it’s the fan that gives the new Mac Pro its cylindrical shape.

ADAM GARSTONE reviews the ‘something special’ that Apple’s Tim Cook promised the tired-of-waiting Mac Pro users. Yes it’s the new Mac Pro. Not like the old one in any way.

Trash can? R2-D2 gone to the Dark Side? Spock’s espresso machine? Whatever you call it, Apple’s new Mac Pro is the most radical personal computer on the market today. It’s also targeted at a very specific market segment, which is summarised with the rather general catch-all of ‘imaging professional’ – moving picture post-production, photographers, scientific visualisation. You and me, in other words. If you want a computer for playing Call of Duty, you’re shopping in the wrong aisle.

Whilst most computer manufacturers release new products that are simply updates of the familiar ‘beige box’, Apple, very rightly, point to the stagnation in CPU performance over the last couple of device families. The latest Intel Haswell architecture is only 6-8% faster than 2011’s Ivy Bridge devices, so if you want a step up in performance you have to get it elsewhere – and the new Mac Pro finds it in its Graphics Processing Units (GPUs). As a result, Apple launched the Mac Pro on its 4k video performance – even the ‘base’ model will drive three 4k displays.

The hardware, then, consists of a single CPU – your choice of 4 cores at 3.7GHz, 6 cores at 3.5GHz, 8 cores at 3GHz or 12 cores at 2.7GHz – and two AMD FirePro GPUs – the D300 with 2 teraflops each, the D500 at 2.2 teraflops or the D700 with 3.5 teraflops each. In case you are wondering, a teraflop is a million, million (1,000,000,000,000) floating point operations per second, and a floating point operation is any mathematical operation on a non-integer number – for example 254.978 + 16.3. So that’s a lot of sums being done every second.

These three main number crunchers (the CPU and two GPUs), along with all the other bits that get hot, are bolted to a triangular heat sink, with a custom fan on the top pulling air up through it – it’s the fan that gives the new Mac Pro its cylindrical shape.

There is plenty more innovation going on inside the Mac Pro. The ‘hard-disc’ is actually a custom SSD attached directly to the PCIe (Gen 3) bus, which gives it amazing speed. Launching most software is instantaneous – no icon bouncing in the dock. Just click on the application and the window opens. Even Avid Media Composer launches in just a few seconds – on lesser machines I usually get a cup of coffee in waiting for it.

All this clever electronics is housed in metalwork of exquisite quality. Putting aside the glossy ‘trash can’ exterior (which I happen to like), the interior is constructed of black, anodised aluminium alloy, machined to perfection. I have never seen machining and fixings like this in any computer before.

 Thunderbolt 2 is a connection game changer with up to six daisy-chaining peripherals for each output and there are six of them. Thunderbolt 2 is a connection game changer with up to six daisy-chaining peripherals for each output and there are six of them.

Much has been said – or bitched – about the lack of internal expansion, and that major components, like the CPU and GPUs can’t be changed (easily) – though the memory is easy to upgrade and the SSD is removable but has an Apple defined connector. Not being able to change CPU and GPU could be seen as a problem to some people. I have changed the graphics card on every Mac Pro I’ve owned, but then they were usually shipped with pretty terrible cards – you can’t say that of the AMD FirePros in the new machines. Personally, I don’t have an issue with the lack of internal drive bays. Every edit or graphics suite I have every been in has used external drives of some sort as main storage – either local discs, or remote SANs – and the Mac Pro comes with 6 Thunderbolt 2 ports for displays and peripherals.

Each Thunderbolt 2 port is good for 20Gbits/s – though you have to be a little careful how you connect devices to get maximum speeds. The Mac Pro contains three Thunderbolt controllers, each with two ports addressing connectors 1&3, 2&4, 5&6 – note that the last one does HDMI as well. If you connect two very high speed devices to ports shared by a single controller, then your bandwidth can suffer – I found that read speeds of LaCie’s lovely ‘Little Big Disk Thunderbolt 2’ dropped from around 1175MB/s to around 900MB/s if connected to the same controller as a display, for instance.

The Thunderbolt ports can also be used as fake Ethernet connections, allowing computer to computer connections at 10Gb/s (raw – you seem to get about half that as a data transfer rate). This raises the intriguing idea of connecting a fast RAID disk to your Mac Pro and sharing the disk with several other Macs over Thunderbolt. It wouldn’t provide the management features of a real SAN, but it would give you a quick and dirty file share – say between edit and grading suites.

Part of the data specification of Thunderbolt is, basically, an extension of PCIe, so it’s no surprise that there is variety of boxes on the market that allow you to connect PCIe cards – in an external chassis – to your Mac Pro. Although Thunderbolt 2’s 20Gbit/s may sound fast, it’s nowhere near the capabilities of, say, a 16 lane, Gen 3 PCIe connector – which will transfer 128 Gbits/s (actually, there’s some encoding overhead, but that’s close enough). Also, not every PCIe card on the market will work across a Thunderbolt extension – it’s driver dependent. Nevertheless, if you still need a RED Rocket card, or a Fibre Channel card for your SAN, then they will generally work – expect to pay about £255 + VAT for a single card adapter.

There are currently two Thunderbolt solutions for 4k I/O – AJA’s io 4K and Blackmagic Design’s Ultrastudio 4K. Unlike the frustrations of trying to get these products to work on a Windows PC, life couldn’t be easier with the Mac Pro. Download the software from the company’s website, plug-in the unit, and Break Out Box is your uncle. The AJA is slightly more complex than the Blackmagic here, as there are separate plug-ins for Adobe and Avid, but only the laziest of lazy gits would call that a problem. Both units are pretty similar in concept, with the AJA providing more analog audio I/O, and HD downconversion from 4k, but the BMD has 6G SDI, proper XLRs for its stereo audio and LTC, and a neat little LCD on the front panel which shows output or input video for confidence monitoring. It also has hardware buttons to select video and audio inputs, as well as software control, whereas the AJA requires you to use their control software. The BMD has an annoyingly loud fan but is much cheaper than the AJA (street price £590 plus VAT plays £1520 plus VAT). The best one is, er, well, both of them.

 Graphics include two AMD FirePro GPUs – the D300 with 2 teraflops each, the D500 at 2.2 teraflops or the D700 with 3.5 teraflops each. Graphics include two AMD FirePro GPUs – the D300 with 2 teraflops each, the D500 at 2.2 teraflops or the D700 with 3.5 teraflops each.

Performance

From the moment you turn it on, the new Mac Pro impresses. Our review unit – an 8 core, 3GHz CPU with D700 GPUs, a 500GB SSD and 32GB of memory – boots from cold in 16 seconds, mostly thanks to the speed of the SSD, which Blackmagic’s Disk Speed Test clocked at over 990MB/s write and 940MB/s read – that’s faster than a Promise Pegasus 2 R6 RAID array!

With the arrival of the Mac Pro, Apple also updated FCP X (to version 10.1) to optimise it for the new architecture. It seemed a good starting point to see what the machine is capable of, pending optimisations from other vendors.

FCP X is now a very different animal from the cub that escaped, half-grown, from Apple R&D in 2011. It’s matured, sprouting some of the whiskers that were so obviously missing back then, and on the new Mac Pro it roars. In a simple playback test, the review machine would simultaneously play 10 streams of 4096×2160 ProRes 422 (HQ), each with 50% opacity, without dropping frames. The test was performed with background rendering disabled and with playback set to “Better Quality’ rather than “Better Performance’. The HP Z820 we tested two months ago only managed five tracks in Premiere Pro in an identical test, and that computer had an NVIDIA Quadro K6000 graphics card, for which Premiere is highly optimised. If you just make a multiclip (hence there are no opacity calculations to be done) then the new Mac Pro will play back 16 simultaneous 4k clips at full resolution with no rendering. That’s pretty impressive. Effects are also GPU enabled and are super fast, and it’s worth noting that Motion shares FCP X’s optimisations.

Unfortunately, the REDCODE RAW plug-in for FCP X is written by RED and is not (yet?) optimised for the new architecture, and it won’t play back a single stream at full resolution without stuttering, though you can get two streams in ‘Better Performance’ mode.

All is not lost for RED editors, however – even if you don’t have a Rocket card (which is supported for playback by FCP X). If you enable background rendering, your timeline is crunched incredibly quickly. Apparently, background rendering makes full use of the GPUs – presumably bypassing the RED plug-in somehow. So you just chuck the 4k REDCODE files onto your timeline and, by the time you’ve paused to rub some fingermarks off the shiny casing of your new Mac (something you spend a lot of time doing), the clips are all rendered and you can edit away.

Apple have improved the performance of other areas of FCP X as well, for instance it now no longer chokes with big projects. I took a feature film from FCP 7 – through the third party app 7toX – into FCP X and, although the conversion wasn’t 100% successful, at least FCP X handled the vast number of clips, and would play the timeline – though there was a tiny delay before going into play. The annoying library structure of FCP X has also been rationalised, clip in/out points are now not only stored but you can mark favourite segments (nice!), and it’s possible to have two monitor windows open, like Avid’s Composer window or FCP’s Browser and Canvas windows (phew). I still think that the magnetic timeline causes more problems than it solves – including, I suspect, being at the root of FCP X not having an audio mixer (an inherently track-based thing), but it’s now quite possible to edit complex work on it (many features are actually way ahead of other NLEs), collaborate on that work with other software packages, and for 4k work on the new Mac Pro (or, indeed, on any other platform) it’s the fastest of the bunch.

That may not be true for long though. Although it wasn’t released at the time of this review, the next version of Adobe Premiere Pro is rumoured to be heavily optimised for the new Mac Pro. At the moment, the Mac release won’t play a single REDCODE RAW clip without stuttering, but the new version is reputed to use one of the GPUs for decoding and debayering, leaving the other free for effects. Having seen the remarkable performance of DaVinci Resolve with REDCODE RAW files (see later), I have little doubt Adobe’s performance claims are true. Premiere manages a couple of streams of ProRes at full resolution, but 8 tracks at 1/2 res. Again, I would expect that to improve dramatically with the new optimised release.

Like FCP X, Avid Media Composer relies on software supplied by RED for its AMA playback of REDCODE RAW, and it seems to have much the same performance – not being able to play a single track in full quality, but managing a couple in performance mode. It fares a little better with ProRes 422 (HQ) files, managing a stutter-free single track in 4k full quality, and a couple in performance mode. As with the PC version of MC7, this doesn’t seem to be limited by CPU bandwidth, which doesn’t stray above 50% even with 4 stuttering tracks of ProRes. Neither is it entirely down to RED’s software, as REDCINE X plays a track of REDCODE RAW in real time, at full resolution – though this does use a serious percentage of the CPU bandwidth.

To really see what the new Mac Pro can do with REDCODE RAW you have to look at DaVinci Resolve. Of course, colour grading isn’t so much to do with how many tracks you can play simultaneously – it’s how much processing you can do on a single track that counts. On the new Mac Pro, Resolve played 4096×2160 REDCODE RAW files on Full Res Premium decode quality without any issues. I then added a fairly complex but realistic grade, consisting of nine nodes with a rotation, various colour corrections including tracked masks, and a blur. Resolve would still play this back at full frame-rate, with the GPU indicator at about half-mast. I was so surprised I had to check a couple of times that I really was using Full Res Premium decode. With ProRes 422 (HQ) files I could add even more nodes.

I brought over a 2k project from my own Resolve setup, as I knew that several of that project’s clips dropped below full frame rate on that system – an old style, 8 core Mac Pro with an NVIDIA Quadro K5000 driving the displays and four NVIDIA Quadro 4000 cards in an external PCIe expansion unit dedicated to Resolve. Amazingly, in comparison to the struggling, huge, old Mac Pro with its giant, noisy external processing unit, the tiny new Mac Pro didn’t even blink, playing the entire timeline at 25fps with no drop in the GPU indicator. Does anyone want to buy an old Mac Pro and bunch of NVIDIA cards?

I did notice that all this GPU activity made the Mac Pro’s fan speed up a little – though I could only tell by running a diagnostic tool, not by any noise increase – so I thought I would tax the heat dissipation a little further. I used REDCINE X convert a load of 4k files to ProRes, as this maxes out all the CPU cores. I then, simultaneously, ran FCP X on looped playback of a timeline with 10 adjustment layers, each with a variety of effects from ‘looks’ to gaussian blurs. Remarkably, the timeline played without dropping frames, though the audio went a bit odd – audio playback is CPU dependent whilst the video is mostly being handled by the GPUs. With all three processors being taxed this way, the fan ran up from it’s normal 770 rpm to around 1350 rpm. The top of the unit got noticeably hotter and the diagnostic software reported that the GPU temperatures went up to 82°C and the CPU temperature to 77ºC (from their normal temperatures in the low 30s). The fan was still extremely quiet, even at this speed. It’s worth noting that the CPU temperature was still well below Intel’s specified maximum of 85ºC, but that if the room had been warmer (the Mac Pro is rated up to 35ºC) the fan would have to have run faster to prevent the CPU from automatically turning its clock speed down to reduce its power dissipation. It’s vaguely possible, therefore, that users in hot climates who run ridiculous tests like mine may suffer from a louder fan, or see some performance falloff, though if I was working in a room at 35ºC my performance would suffer more than the computer’s.

It isn’t easy to work out which Mac Pro to buy. Various CPUs are available (at different prices) with each choice providing a different number of cores, but at different clock speeds.

Unfortunately, it isn’t possible to say that as the number of cores (and hence cost) goes up, so will the speed of your computer – it’s highly dependent on the software you are running. Basically, if the software can’t (or won’t) take advantage of all those cores, then you are better having the faster clock speed. However, if the software isn’t using all your cores, it’s possible that Intel’s Turbo Boost will kick in on the cores that you are using (that’s dependent on a whole load of factors including temperature). The 4, 6 and 8 core models all have the same maximum Turbo Boost frequency, so there probably won’t be much penalty (other than in your wallet) for buying a CPU with more cores, even if you are running a single-threaded application.

Cores count, however, when you’re transcoding video. All of the mainstream applications – Apple’s Compressor, Avid’s Sorenson Squeeze,  Adobe’s Media Encoder and so on – take full advantage of as many cores as they can get.

So, although the 12 core machine will outperform the others when it comes to transcoding, you probably won’t get the most bang for your buck in general use. I suspect that the ‘sweet spot’ on the price/performance graph is the 6 core machine – and that’s what I would buy, spending another £800 on getting the D700 GPUs. I’ll live without the fastest transcoding performance that money can buy, as its something I only do once a week or so, and I’ll pocket the extra £2400 – or spend it on a dedicated render computer. I’ll also buy a lint-free cloth, to wipe off the finger marks, and I shall polish her, and love her, and call her Lola…

Conclusion

Much vitriol flooded the Internet when the Mac Pro pricing was announced, and they are expensive computers – the unit we tested would cost £5540 – but, as many pundits have pointed out, they are cheaper than a similarly specified PC from any of the main manufacturers. Sure, you could knock something together yourself, from ‘no name’ parts, for less money, but would you trust it?

Others have pointed out that a cheaper PC will run their favourite shoot-em-up faster, but again that’s missing the point. The new Mac Pro is aimed squarely at applications optimised for those amazing GPUs. With FCP X and Resolve leading the way, and Adobe following quickly behind, hopefully we’ll see other software vendors tweaking their code for this ultimate Mac.

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