Upgrading and Analyzing Apple's Nehalem Mac Pro
by Anand Lal Shimpi on July 13, 2009 5:00 PM EST- Posted in
- Mac
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.
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jamesst - Tuesday, July 14, 2009 - link
"The Lexar reader is FireWire 800 (woo!) and the iSight is FireWire 400; I can’t use the iSight on the new Mac Pro."You can still use your Firewire 400 iSight camera on the Mac Pro's Firewire 800 ports. All you need is a Firewire 400 to Firewire 800 cable. I know that Belkin makes just such a cable and I even purchased one at my local Apple Store here in Raleigh, NC.
joelypolly - Monday, July 13, 2009 - link
I have actually had something similar happen to a socket I was working on. It was a matter of finding a sewing needle and moving each "pin" back to the original position.HilbertSpace - Monday, July 13, 2009 - link
It would be interesting to try swapping the 2-socket tray with a 1-socket Mac Pro, and see if it works(?) Would be cheaper to buy the 2-socket board and upgrade yourself, no?MonkeyPaw - Monday, July 13, 2009 - link
Are FB-DIMMs going to disappear from the market? While at first it doesn't sound Mac-related, original MacPro owners might soon be running out of memory upgrade options (though I doubt they've held out this long to upgrade). It wasn't cheap to start with, but it seems like it was Band-Aid technology. The IMC was the answer, but FB-DIMMs were a stop-gap until Nehalem-Xeons could arrive. Perhaps a memorial article for the technology is needed?JimmiG - Monday, July 13, 2009 - link
Ok so I get it, even the "cheap" Mac Pro uses a Xeon, not an i7... But for all intents and purposes, it's an i7 920.Who in their right mind would pay $2,500 for a i7 920 system with 3GB of RAM, 640GB HDD and a rebranded Geforce 9500 GT? You can build a similar PC (or hackintosh) with the same specifications for the a fraction of the price - in fact you could also bump the RAM to 6GB and throw in a 1TB drive and a 4870 1GB or 4890 if you wanted and still stay *well* below that price point, even if using quality components and case.
The Mac Pro isn't even shiny!
plonk420 - Tuesday, July 14, 2009 - link
did you read page 10?MrDiSante - Thursday, July 16, 2009 - link
Did you read his comment?ltcommanderdata - Monday, July 13, 2009 - link
Another great in depth review. Your experiences with upgrading the processors were particularly interesting although I don't think it'd be something I would try.I just wanted to suggest you Boot Camp the Mac Pro and run the benchmarks needed to add 2x2.26GHz Gainestown and 2x2.93GHz Gainestown results to the Anandtech Bench. It might also be interesting to get a sample of the new nVidia GTX285 Mac Edition. It would certainly address the 1GB of VRAM concerns and would be cheaper than getting the HD4870 if you need 2 dual-link DVI ports since you don't need to buy that finicky adapter. There really aught to be DVI to mini-DP adapters though for people who still want to use the 24" LED display.
http://www.glbenchmark.com/result.jsp">http://www.glbenchmark.com/result.jsp
Oh and for interest, there turns out to be a 3D benchmark comparing the various iPhones to other cell phones. It's called GLBenchmark and needless to say, the iPhone 3G S is a screamer. They are also detecting the iPhone 3G S GPU as a PowerVR SGX 535.
ddobrigk - Monday, July 13, 2009 - link
Actually, the Nehalem-EX's octo-core possibility is a no-go for now. It is a future product and has not been launched yet.Also, a little bit of nitpicking, but it won't use LGA1366 like these Xeons, it'll use LGA1567, because each CPU will sport a 4-channel memory controller.
In addition, it'll sport 4 QPI links, and its intended target are 4-way and 8-way systems, not really 2-way systems. A few rumors exist about some integrators being interested in 2-socket systems, though we're still a few months from actually seeing any LGA1567 motherboard on display, AFAIK. All we saw was an Intel Demo about it.
Don't know if Apple intends to go with 2-socket nehalem-exs, anyway, because when Nehalem-EX really hits the market, there'll also be the 6-core westmeres, I think. In any case, we're way beyond a reasonable number of cores for the typical user. :D
BrianMCan - Friday, July 17, 2009 - link
MacPro's really aren't meant for typical users ;)Scientific, Video/Movies, 3D, and advanced users who may do many things including the already mentioned, or many things at once. Always other things I can be doing while some video is rendering, including playing some Civ 4, or starting the next video project, researching upgrades & repairs for customers, stuff like that.
Although I personally may wait for the 2nd gen Nehalem MacPro's before I upgrade from my first gen MacPro, other than raw processing power, it does most of what I need efficiently enough.