The new Mac Pro: desktop mainframe

The tiny little power-packed tube is engineered like a 1960s mainframe computer: a central processor with a lot of I/O. That makes the economic case for it very different than for other PCs.
Written by Robin Harris, Contributor on

For decades, IBM mainframes were relatively wimpy processors with lots of I/O channels that could support dozens of disks, printers, terminals and comm links. The new Mac Pro is hardly wimpy, but its heavy focus on connectivity — 6 Thunderbolt ports, 4 USB 3.0, HDMI and dual GigE — makes it closer to the mainframe architecture than a traditional workstation.

The new Mac Pro is all about configurability. Not within the tube, but as a system.

Professional users have a different set of economic priorities than consumers. These include:

  • Reliability and availability. Uptime is crucial and the ECC DRAM a win.
  • Performance. Professionals make more money when they get more work done. It doesn't take much more performance to justify a faster system.
  • Specialized options. From 4K displays to fiber Channel networks to specialized I/O cards, professionals often invest as much or more in their peripherals than they do in their system processor.

What do some of these systems look like?

  • A serious coder might have an 8-core system with five 30-inch monitors and two fast RAID arrays.
  • A 4k video editor might have three monitors, a fast external array, Fibre Channel, a 4K optimized video card, a specialized control deck for editing and color grading and high-end audio and video I/O interfaces.
  • A musician might have two or three displays, a fast array, multiple MIDI-based instruments and high-end audio interfaces.

What distinguishes each of these configurations is that the attached peripherals may cost more than a Mac Pro. This changes the economics of a system in important ways.

If you have $12,000 worth of peripherals, then $2500 for the computer is less than 20 percent of total investment. Not a big deal.

If you are a professional billing $100k annually, a system that reduces wait time by 5 percent can pay for itself in less than six months. A bigger deal.

For many pro users the ability to add as many PCIe slots as needed will be key. Several Thunderbolt card cages are available today, making it possible to build configurations impossible with the current design.

And this means that once you've bought your PCIe cards and enclosures, you can upgrade your processor with much less hassle. Upgrade what you need when you need.

The Storage Bits take
The new Mac Pro is designed for these kinds of users. The abundant I/O capabilities make this the most configurable and expandable Mac Pro ever made.

It will find a small but appreciative and influential audience. For people who require specialized I/O and make money from their system, the new Mac Pro will be very attractive.

Which is not to say the new design is perfect. Having all of that I/O going through flimsy thunderbolt connections is not ideal. Nor will the "light on rotate" be useful when a half-dozen cables are plugged into the back of the Mac Pro.

But these are minor issues that enterprising accessory makers will solve. For the few people that need what a Mac Pro offers, they'll have a machine they can use for years.

Update: Seeing the objections to the term "mainframe" let me re-iterate and expand. The IBM 360/370 families were channel-oriented systems. For example, a mid-range IBM 360 model 50 supported up to 768 "I/O units" - disk, drum or tape drives - and up to 1,984 slow-speed devices - terminals, card readers and printers. While I doubt anyone went to these maximums, the point is that these were I/O, not CPU-centric, machines. Likewise with the new Mac Pro: it is a CPU with a lot of fast Thunderbolt I/O for external expandability.

Few appreciate just how fast Thunderbolt is. It makes it possible to edit 4k video on a 2012 MacBook Air. Having 6 of these channels on a Mac - supporting up to 36 devices, makes the Pro more like a mainframe than a current high-performance workstation. While I doubt that will satisfy everyone - anyone? - that's the basis for the "desktop mainframe" comparison. End update.

Comments welcome. Part of me wishes I was still editing videos so I could justify a Mac Pro.

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