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


View All Comments

  • vladik007 - Wednesday, August 9, 2006 - link

    Flashing PC video cards to work on G5 was possible and in my own experience also rock solid. I have 2 G5;s at home ( one 2.0Ghz very 1st released ) and 2.7ghz. PNY 6800 GT with 2120 firmware has worked for over a year now and ZERO crashes in that time in both of them.

    So if PC videocards will NOT work in Mac Pro by just simply sliding in , firmware flashing will.
  • ViRGE - Wednesday, August 9, 2006 - link

    Anand, has Apple/Nvidia/ATI commented on what video card compatibility will be like with the Mac Pros over the PowerMacs? With the PowerMacs, PC video cards were incompatible due to OpenFirmware and more importantly endian issues. The Mac Pro however is EFI and not OpenFirmware, and there are no endian issues, which gives everyone a lot of hope that the system may be able to take on vanilla 7900's and the like.

    Has anyone said anything on this matter going one way or another?
  • blwest - Wednesday, August 9, 2006 - link

    I'll know tonight when I try to slap my 7800gt into the box! Reply
  • artifex - Friday, August 11, 2006 - link

    He never came back... maybe he blew up his new Mac Pro? Reply
  • archcommus - Wednesday, August 9, 2006 - link

    Given that this hardware is just like a PC and 100% x86, and given that the new OS X is designed to run on that hardware, what is REALLY the obstacle in getting OS X to run on our own Windows and Linux machines? Reply
  • Missing Ghost - Monday, August 14, 2006 - link

    yep OSX does not use the bios. It needs efi Reply
  • AaronAxvig - Wednesday, August 9, 2006 - link

    They still have the EFI boot system, no? Reply
  • mrgq912 - Wednesday, August 9, 2006 - link

    Back when Apple made they announcement that they were going to switch from power pc to intel cpus. I thought why intel and not amd? Now it seems that Intel must have shown them what their new hardware is capable of, and Apple didn't even need to think twice about the move. Good call by apple.

    But I still won't buy closed system like Mac pro.
  • hmurchison - Thursday, August 10, 2006 - link

    Please don't take offense to this but that was really a silly statement. Back in the days when you had differing hardware between Macs and PCs you could say the Mac was more closed. Nowadays you have the ability to run OS X, Windows and Linux simultaneously and a lot of hardware will just plug and play with the appropriae minidrivers in the OS. Reply
  • mrgq912 - Saturday, August 12, 2006 - link

    none taken. i didn't know that mac pros allowed you to switch video cards and memory. I always wanted to use the mac os for every day use, and have windows for games and such. But now the only thing stopping me is the price. Reply

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