The Crossroads of Simplicity and Sophistication

Choices. Choices. Apple doesn’t like to present the end user with many choices. Too many choices can confuse, if left unchecked they can become overwhelming. The overburdening of choices is something that most PC OEMs fall victim to. I recently spoke with ASUS and brought this up in a conversation about the Eee PC. Three and four digit model numbers are how you tell one Eee PC apart from another. Perhaps you have the Eee PC 901, or the Eee PC 1000HA or the S101. To an enthusiast who has time to research these things, the model numbers aren’t that hard to figure out - it’s easier than Calculus after all. To someone just looking to buy “one of those Eee things”, it’s overwhelming.

Try buying an Apple notebook and you’re faced with two models: the MacBook and the MacBook Pro. If you’re a consumer, buy a MacBook, if you’re a professional buy the Pro version. Then just select your screen size and you’re done. That’s how Apple wants it to work and for the most part, it does. Very well.

Apple’s simple approach works quite well for consumers, but once you start getting into the high end content creation world it’s not quite so easy. How do you simplify the decision between two very fast cores and four slower cores or eight even slower ones? It wouldn’t really fit within Apple’s well kept home to ask its customers whether they run predominantly single threaded, lightly threaded or heavily threaded applications. Much to my surprise, the two new Mac Pros do effectively that. They present the end user with an option to choose four faster cores or eight slower ones. And there’s much more to the numbers that what Apple publishes on its own website.

These are the CPUs Apple offers on the new Mac Pro:

Apple Mac Pro (2009) Quad Core Model Eight Core Model
Default CPU 1 x Xeon W3520 (2.66GHz) 2 x Xeon E5520 (2.26GHz)

 

The clock speed difference appears to only be 17% at first glance, but there’s much more to the story.

Four or Eight Cores and the Magic of Nehalem

There are effectively three classes of applications that we have to consider when wondering whether or not the new Mac Pro is indeed a good buy. On one end of the spectrum we have single-threaded applications and tasks.

These days CPU performance improvements happen along three vectors: ILP, clock speed and TLP. The first vector of performance improvement is ILP (Instruction Level Parallelism). These improvements are changes to the micro-architecture. They could be as simple as adding a larger/faster cache, or as complex as a faster/more capable SSE unit. These days there are minor improvements in ILP between microprocessor generations. The second vector, clock speed, is also fairly stagnant. The Nehalem based Xeons run at about the same clock speed as the Woodcrest, Clovertown and Harpertown based Xeons that the older Mac Pros used. The final vector, TLP (Thread Level Parallelism), is where we’ve seen some of the biggest gains this round. As the name implies, execute more threads in parallel and you can get more performance. You increase the number of threads you can execute by running multiple threads on a core (SMT or Hyper Threading) or by adding more cores to a chip. Quad-core is still the sweet spot configuration for Xeons, but the Nehalem architecture brings Hyper Threading back to the limelight and now each of those four cores can work on two threads of instructions at the same time.

Well let’s look at how ILP, clock speed and TLP compare from Harpertown to Nehalem (for more details on what makes Nehalem tick, err tock, be sure to read our architectural analysis):

Apple Mac Pro (2009) vs Apple Mac Pro (2006 - 2008) Upgrade Downgrade
Instruction Level Parallelism (ILP) Faster memory access
Minor microarchitectural updates
Smaller L2 caches
Clock Speed Minor clock speed advantage in some cases Minor clock speed disadvantage in others
Thread Level Parallelism (TLP) Large L3 cache shared by all cores
2x threads per core (Hyper Threading)
 

 

Looking at the table of improvements you should already know where to expect the Nehalem Mac Pro to excel. With each chip being able to execute twice as many threads as those used in the old Mac Pro, if you’re running a well threaded application then you’ll certainly see performance improvements on the new Mac Pro. What sorts of applications are “well threaded”? Generally things like 3D rendering and professional video encoding. The easiest way to find out is to fire up activity monitor and see how many of your cores are taxed while you’re using your system. If all of the bars are full of blue on a quad-core machine then you’d probably appreciate a Nehalem Mac Pro.

The clock speed improvements are minimal. In a non thermally constrained environment you can add 133MHz to whatever clock speed Apple puts on the box. So the 2.26GHz Mac Pro will most likely run at 2.40GHz and the 2.66GHz Mac Pro will spend most of its time at 2.80GHz, if you’re doing something CPU intensive that is. This is of course do to Intel’s Turbo mode.

Improvements: Limited but Important Understanding Nehalem’s Turbo Mode
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  • wackazong - Wednesday, September 9, 2009 - link

    Hello,

    this may be the right place to ask: What's the difference between the Xeon and the (much cheaper) i7 processors? Couldn't you put an i7 into a Mac Pro?
    Reply
  • sdevenshire - Saturday, August 29, 2009 - link

    Hi,

    I purchased a 2xQuad core mac in Jan 2008 and I would like to upgrade the cpu to the new Nehalem. Apple suggested it could be done but they don't do it. I contacted a number of Mac repair places and they said it can't be done. I realize that upgrading the cpu probably means upgrading the motherboard, but that's fine with me.

    Any suggestions on where I could get this done or where I might get instructions for doing it myself?

    TIA,
    Shane
    Reply
  • 529th - Thursday, July 30, 2009 - link

    If you’ve read our Nehalem articles you’ll know that each chip has three 64-bit wide memory controllers, thus you’ll want to install DIMMs in triplets. You can install four DIMMs, but accessing memory in the fourth module will be slower - something you’ll never notice if you’re wondering. ???

    This is hindering me from buying a 4 channel UD3R X58 board. My main goal of an i7 build is for editing AVCHD files through Premiere Pro CS4. Being that tri channel will get me 6g and PP CS4 likes more memory, will adding memory to the 4th module screw things up?
    Reply
  • newrigel - Tuesday, July 28, 2009 - link

    Man, take your hackysack and go buy some laundry soap to clean the crap out of your drawers! You guy's talk about a couple thousand dollars like it's buying a damn house or some huge purchase LOL!
    Macs are really cost efficient and yes... PC's are cheaper but who gives a damn! If you want to be cheap... be cheap! Hackintoshes (LOL) are just that... a POS and your getting what you pay for! You cheap asses probably hit your ol' ladies up for gas money to get to work hehe...
    MACS RULE!
    Reply
  • ditchmagnet - Monday, July 27, 2009 - link

    Just for fun I went to apples site and customized the mac pro, I just maxed out the hardware choices and then went to newegg and priced out an equivalent PC (Server board, with the same CPUs and everything except more RAM)
    Total for the apple including shipping and tax is over $20,000
    the newegg build is under $9,000
    I bet my 920 build at 4.5ghz is faster than the mac pro though, and all for under $1000
    Reply
  • moltentofu - Tuesday, July 21, 2009 - link

    wander over to the egg and buy a lian li. No flashy lights really, no idiot clear side panels. For some reason the hard drive access light and the power light are different colors on mine though.

    You can get a combo case with a seasonic 550W power supply with it. I put a phenom II x4 3.2Ghz 16 Gigs of RAM and a 1 Gig 4870 in there with aftermarket cooling all around (air not liquid) and it cost me 900 bucks - all from the egg.

    If you think you're going to find performance arbitrage basically anywhere in the market you couldn't be wrong-er. Just pick your price/performance point and stick to it.

    Thanks for the awesome reviews as usual Anand!
    Reply
  • moltentofu - Tuesday, July 21, 2009 - link

    With one big 'ol caveat to the arbitrage thing and that is: building your own system really does seem to be cheaper right now, and also I can't find component setups in the big name companies right now that make me quite happy.

    I miss when Dell Outlet used to be affordable. I'm afraid these Macs are just waaay out of range of my meagre salary.
    Reply
  • fmaste - Monday, July 20, 2009 - link

    Everybody talks about how expensive the Mac Pro is, but, has somebody compared with other brands? Look at this:

    I customize two Dell Precision Workstations with the same components as the base configurations Apple offers for the Mac Pro.
    The results!!

    Mac Pro Quad-Core: $2,499.00
    Dell Precision T5500: $3,427

    Mac Pro 8-Core: $3,299.00
    Dell Precision T7500: $3,427

    BOTH APPLE OFFERS ARE BETTER!!!!!
    Both with the same processors, same amounts of memory at the same speed.
    The only difference is instead of a NVIDIA GeForce GT 120 with 512MB you get a 256MB NVIDIA® Quadro® NVS 295. And that Dell options have hard drives with less capacity, 500GB vs 640GB. I also added the second Gigabit Ethernet card to both Dells. Dell has no bluetooth option and you may need to add a sound card to them.
    Remember, you get a more expensive PC with windows Vista and an ugly chasis.
    Reply
  • fmaste - Tuesday, July 21, 2009 - link

    And here is HP

    Mac Pro Quad-Core: $2,499.00
    Same specs configurable HP Z800 Workstation: $3,942.00

    Mac Pro 8-Core: $3,299.00
    Same specs configurable HP Z800 Workstation: $3,702.00
    Reply
  • excalibur3 - Friday, July 17, 2009 - link

    So when you hypothetically created your i7 hackintosh, what were it's specs? I'm thinking about doing this (as a thought experiment only of course) and I'm wondering what such a system would price out. How would I know what motherboard to use to be compatible? Reply

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