CPU Analysis

The biggest part of Apple's Mac Pro announcement is of course the move to Intel processors and as many had predicted, Apple chose to go with Intel's Woodcrest based Xeon processors instead of Core 2 for the Mac Pro. Architecturally, the Woodcrest based Xeons are no different than the Conroe based Core 2 processors, so you get the same level of performance we showcased in our Core 2 review. With Xeon you do get the ability to go to multi-socket systems and a faster FSB, both of which are not possible with Core 2. Note that the Woodcrest based Xeons use a 771-pin LGA socket that is different than the 775-pin LGA socket used by the desktop Core 2 processors, so you can't swap them if you wanted to.

One of our biggest fears with Apple's use of Xeon instead of Core 2 is that it would put pricing of the Mac Pro above and beyond reasonable, but consulting Intel's price list left us pleasantly surprised:

Core 2














Believe it or not, Intel's Xeon 5160, a faster alternative to the Core 2 Extreme X6800 is actually priced lower. At the very high end, from a purely processor standpoint, it makes sense for Apple to opt for the Xeon over the desktop Core 2 route because it's cheaper. It's not often that you see server/workstation processors priced lower than their desktop counterparts, so Core 2 Extreme owners should feel a bit ripped off (but the excellent performance can definitely numb the pain).

The Xeon 5160 aside, you're basically paying a premium for going with a Xeon over a Core 2, despite the fact that most of the time all you're getting is a faster FSB. While the 1333MHz FSB will do something, in the case of the Xeon 5150 vs. the Core 2 Duo E6700, you're paying 30% more for that advantage. Compared to the E6400, the Xeon 5130 costs 40% more and is clocked lower, although it has a larger L2 cache.

If you want to put Apple's performance in perspective, the slowest Mac Pro you can get is outfitted with a pair of Xeon 5130s. In single threaded applications, we'd expect the system to perform similarly to a Core 2 Duo E6400 system. In well multi-threaded applications, you'd be looking at significantly higher performance (dual dual core vs. single dual core).

The Xeon 5150 will obviously be a bit faster than the equivalently clocked Core 2 Duo E6700, thanks to the faster FSB. As we saw in our Core 2 review, in most Windows desktop applications we saw a 0 - 7.5% increase in performance, with the average increase being 2.3% due to the faster FSB. Multithreaded applications won't necessarily take better advantage of the faster FSB, it really depends on the application itself.

And obviously the Xeon 5160 will be faster than the current fastest desktop processor, Intel's Core 2 Extreme X6800. The performance advantage won't be tremendous, but it will be there.

If we were simply looking at single CPU configurations, Apple's decision to choose Woodcrest/Xeon over Conroe/Core 2 would have been an effort to keep average selling prices high, but none of the Mac Pros are single socket systems. Instead, Apple made an expensive but important move with the Mac Pros; by choosing Xeon, Apple can implement two sockets on the motherboard, which today means you can execute four simultaneous threads (dual dual core). By the end of this year, Intel will be shipping Clovertown, a quad core version of the dual core Xeons you see in today's Mac Pros. If Apple chooses to, with minimal effort, it could release 8-core Mac Pro systems in a matter of months (assuming Intel keeps its accelerated CPU schedule).

With four cores on a single die, the faster FSB matters that much more, so the 0 - 7.5% increase due to the 1333MHz FSB that we saw in our Core 2 review will go up. Seeing as how we were playing with quad core Kentsfield processors back in late May/early June, you had better believe that Apple designed its Mac Pro motherboards with support for Clovertown. While Apple isn't really touting processor upgradability with the new Mac Pro, it wouldn't be too far fetched to think that you could swap a pair of Clovertowns in these systems with no more than a firmware update.

Index The Chipset


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  • michael2k - Friday, August 11, 2006 - link

    fb dimms, found in Mac Pros, are fast serial ram using DDR chips. Reply
  • OddTSi - Friday, August 11, 2006 - link

    Perhaps you missed the part where I said "non-ad hoc."

    I know what FB-DIMMs are, but they're more of a band-aid fix or a hack than a ground-up design.
  • michael2k - Friday, August 11, 2006 - link

    Maybe you misused "ad hoc". Ad hoc means unplanned and temporary. Why do you think fb-dimm is a band-aid or a hack? Because the RAM chips themselves are not serial in nature?

    I mean, are you asking "Is there any designs or plans for serial memory chips?"

    To be cost effective you either have to use existing infrastructure, or create a logical evolution/adaptation of the existing infrastructure.
  • AdvanS13 - Thursday, August 10, 2006 - link

    does anyone know apples market segment share for dual processor workstations? Reply
  • peternelson - Thursday, August 10, 2006 - link

    1) I think a gpu swap will need drivers or firmware updating.

    2) To buy a commodity sata drive is good but it MIGHT require the apple carrier in order to fit into the chassis.

    3) You compare apple memory with commodity FBDIMM.
    In the table you quote Apple's UPGRADE (ie on top of base machine) price against the complete cost of the memory. This makes Apple's pricing appear better than it is. Even then it looks like a ripoff, but also consider they are charging you for the base memory in with the basic system price.

  • aliasfox - Friday, August 11, 2006 - link

    As far as I've read, the Mac Pros come with carriers in all four bays - carriers that don't need cables (ribbon or round). Didn't know the backs of SATA drives were similar enough that they could just be plugged in. Reply
  • JeffDM - Saturday, August 12, 2006 - link

    It's not stated in the Anand article, but all drive carriers are included. Apple's Tech Specs page says it, although it could have been more clearly stated. For what it's worth, I think it is worth downgrading the stock drive to 160GB and spending that difference toward additional drives. Going from 250GB to 160GB saves $75, that price difference would buy you a 250GB SATAII drive. Reply
  • JAS - Thursday, August 10, 2006 - link

    It appears that some people managed to receive their Mac Pro quickly.

  • IntelUser2000 - Wednesday, August 9, 2006 - link


    Check out the memory bandwidth benchmark. Quad channel is needed to match Core 2 systems' memory bandwidth using only dual channel. Dual channel on Xeon 5100 drops to approximately 68% of the quad channel bandwidth. That in numbers is 3.8GB/sec. Not to mention Xeon 5100 series has 25% higher memory FSB. It needs 25% higher FSB and 2x memory channels to achieve the same memory bandwidth numbers the desktop Core 2's can. According to memory latency benchmarks, the latency is also significantly higher on the Woodcrest than Conroe's platform.

    The chipset on the Xeon 5100 is worse in performance than the chipset on the Core 2. It will NOT beat Core 2 because of the 25% higher FSB, it will rather be SLOWER. Not to mention FB-DIMM makes it even slower.

    SpecFP benchmarks also support this:
    Xeon 5160(3GHz/1333MHz FSB/4MB L2/8x1024MB FB-DIMM DDR2-667): 2775
    Core 2 Extreme X6800(2.93GHz/1066MHz FSB/4MB L2/2x1024MB DDR2-800 5-5-5-15): 3046

    Core 2 Extreme gets almost 10% higher in the memory substem portion of the SpecCPU 2K. benchmark, even though it has 2.2% less clock speed than the Xeon 5160.

    Look here: http://www.anandtech.com/IT/showdoc.aspx?i=2772&am...">http://www.anandtech.com/IT/showdoc.aspx?i=2772&am...

    "ScienceMark didn't agree completely and reported about 65-70 ns latency on the Opteron system and 70-76 ns (230 cycles) on the Woodcrest system. We have reason to believe that Woodcrest's latency is closer to what LMBench reports: the excellent prefetchers are hiding the true latency numbers from Sciencemark. It must also be said that the measurements for the Opteron on the Opteron are only for the local memory, not the remote memory."

    Xeon 5160 got 70-76ns in ScienceMark, what did Core 2 get?? It got 36.75. Xeon 5160's ScienceMark latency is higher than Pentium Extreme Edition 965's latency, and twice the latency of Core 2.

    Everest shows the same thing: http://pc.watch.impress.co.jp/docs/2006/0801/graph...">http://pc.watch.impress.co.jp/docs/2006/0801/graph...

    Xeon 5160: 99.1
    Opteron 285: 57.7(seems higher than FX-62 results but this system uses Registered DDR DIMM, you can see in AT's results that AM2 further lowers latency)

    Core 2 Extreme: 59.8

  • dcalfine - Wednesday, August 9, 2006 - link

    Overall, I think this is a very well-designed system, and in price comparisons with Dell, the Mac Pro came out over a thousand dollars cheaper for a similar system. I may be a fanboy, but I can admit that Apple still has some work to do here. As good as the Mac Pro is, I think Apple needs to start having better video options. For starters, the X500 chipset is used, which means that there's only one 16X PCIe lane. Also, Apple should get closer with Nvidia and start working in SLI, as well as FX4500X2 and FX5500. A Vanilla FX4500 just doesn't make the cut anymore. Also, the X500 chipset supports one 133X PCIX slot, which, I think, Apple should have incorporated, since not every expansion card has moved to the PCIe format.

    I'd like to see some speed comparisons between the mac pro and some pcs. I imagine that in most (if not all) test the Mac Pro will come out slightly slower than the PC due to the bells and whistles of Mac OS X, but I'd like to see just how much slower it runs, and how it runs in Boot Camp running Windows/Linux.

    But, yeah. Good goin', Apple!
    And AnandTech, get your hans on one of these ASAP!

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