diglloyd Mac Performance Guide

Visit Thunderbolt Central

100% Kona, 100% Family Owned

Mac Pro Westmere Value Compared to Quad-Core iMac

Last updated August 21, 2010 - Send Feedback

With judicious buying, the iMac system is less money (assuming you need a new display— some buyers do not). When considering a total system (hardware, software, AppleCare, backup drives), the difference is not so much as a percentage, and you also get less for your money with the iMac, more on that below.

With four CPU cores (assuming you choose the fast Intel Core i7), and up to 16GB memory, the iMac can suffice for a serious photographer — for a while at least. And the MPG Pro One can make it into a serious machine.

There is a lot more to a workstation than how fast it runs with a virgin hard drive.

In the real world, you need more and faster storage over time, you need efficient backup, you need reliability, etc.

While the 2010 iMac is gorgeous and nicely done, for what it is, consider the following as compared with a Mac Pro:

  • As-shipped, it is impossible to add fast external drives to the iMac. At best, you have Firewire 800, which runs at 2/3 the speed of a single hard drive and 1/4 the speed of a fast solid state drive (and for volumes over 1TB, 1/3 the speed of a single fast hard drive). Speed varies by drive and by Mac, but it is never fast.
  • As-shipped, it is impossible to add an internal Time Machine backup of adequate size. This forces you to use an external drive (cables, noise, clutter) or something like an Apple Time Capsule.
  • As-shipped, it is impossible to add a mirrored internal backup for increased reliability. Again, you have to go external at extra expense, with the cables, noise and clutter it involves.
  • Impossible to create a 4TB striped volume, a 2TB mirror, etc, since you’re limited to one hard drive and one SSD internally (by Apple, but see the MPG Pro One). Yes, you can do so externally, but it’s nuts to use Firewire 800 on a 4TB volume—just reading the data would take an entire day.
  • As-shipped, impossible to ever have double/triple/quadruple drive speed, and hard drives slow down as they fill up. A year later, with the drive mostly full, you’ll be forced to expand with sluggish FW800. You can never make that as fast as even a single hard drive.
  • As-shipped, slow backup of large amounts of data: Firewire 800 running (for writes) at 1/2 to 1/3 the speed of a single fast hard drive. Backing up 1.5TB of data is at least a 7 hour operation, if you’re lucky.
  • One (1) Firewire 800 port. A thicket of cables and wall warts makes a big mess. Reliability suffers, noise levels go up, performance goes down.
  • Display support: the Mac Pro has three ports, and more can be added.
  • Memory limited to 16GB. That’s usually plenty, but should you start doing big jobs, you’re stuck. A Mac Pro can do 32GB (64GB for the 8-core).
  • Mirror-like screen. It’s beautiful with a dark room and black shirt, but poor room lighting is a visual impediment. The hyper saturated mirror screen is not good for print matching.
  • Want to calibrate the screen for accurate color? Calibration is going to tweak the video card in 8 bits, not tweak the display itself in 10-bit or 12-bit internal to monitor itself. Apple doesn’t supply a hardware calibrator. The NEC 27" display (or 30") is the right choice for photographers.
  • Want to swap or add an internal drive? It’s an involved operation to do anything inside the iMac, and there’s little or no expansion to begin with (one HDD and one SSD or similar). In a Mac Pro, it can be done in a few minutes, by anyone, with near-zero risk (you get 4 bays + a lower optical bay for another hard drive or SSD = 5 drives, and six if you remove the optical drive).
  • Drive failure? On a Mac Pro, replace in under five minutes with a screwdriver, but on an iMac... well, you’re screwed until it’s fixed (don’t forget that external backup drive on the iMac!). Can you as a professional tolerate several days of downtime?
  • If the iMac display goes bad for any reason, you are down while the iMac is repaired. Can you as a professional tolerate several days of downtime? With a Mac Pro, swap in a working display.
  • Expansion— want eSATA, a card with extra USB or Firewire ports, a special video or sound card, etc? No problem with a Mac Pro, but far fewer options with an iMac.

Those are my concerns, but they might not be yours, so if an iMac appeals, fantastic. And for some, the iMac might be all they ever need. No argument there.

But I cannot afford to be down two hours, let alone two days, losing data is not an option, and avoiding that by dangling multiple hard drives off a FW800 port is a noisy and unreliable mess. Finally, the ergonomics of a screen that won’t adjust for the right height is a painful past experience I won’t repeat. So the iMac is a non-starter for my intensive work.

That said, if space were a constraint (e.g., a mobile situation), the MPG Pro One would be perfect.

Adding it up

Setting aside the limitations of the iMac detailed above, let’s look at pricing.

Matching the processor speed exactly is a red herring: the Intel Core i7 is not the same as a Xeon in the Mac Pro, as the tets that follow show.

These prices were obtained on July 28, 2010, and won’t be updated. See this OWC shopping cart for current prices on various parts, and Buying an iMac or Buying a Mac Pro page.

Parts costs below are at OWC prices, at large savings compared to Apple. The iMac is cheaper because it includes the display, but you do lose in functionality, and there’s no real expansion except with slow stuff. But if you already have a display, the picture changes radically— you can put that savings towards a hexacore 3.33GHz Mac Pro. Besides, a wide-gamut color display with reliable hardware calibration in 10 or 12 bits is a must-have for serious photography, and that’s my need.

Note that for the iMac, the upgrade to 2TB drive is an upcharge, and you don’t get the original drive. It’s difficult to swap out the hard drive, so get the 2TB drive, because hard drives slow down as they fill up. If you need more space than the 1TB drive offers, you’ll need to pay for an upgrade, unless you are very comfortable with a tricky install, so always get the 2TB drive. Or solve that headache by adding an eSATA port as port of the MPG Pro One upgrade.

Figure total the system cost, then figure in the limitations of the iMac, and its long-term viability. Think in percentage terms, future expansion, down the road value.

Shopping cart Mac Pro iMac
Base machine $2449 for 2.8GHz quad-core
$2149 for 2.66GHz quad-core (refurb)
2.93GHz Quad-core Intel Core i7 $2199
16GB OWC memory $610 $549
2TB hard drive $139.99
you KEEP the stock hard drive and can use both internally!
$150
Solid state drive (SSD) $629 for best-in-class 240GB drive $750 for inferior 256GB drive
Display $999 built-in
eSATA card $59 not possible
2TB Backup drives (3) $750 eSATA fast $700, slow
Applecare $249 $169
MPG upgrades Starting at $1157 starting at $1079

 


The Speed You Need

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2008-2014 diglloyd Inc, all rights reserved.