The 2009 Mac Pro Value Equation

Apple completely changed the playing field with the 2009 Mac Pro. It's based on Intel's new "Nehalem" CPU architecture, which introduces a lot of new features to improve performance and efficiency.

The Mac Pro's New Brain

Nehalem uses QuickPath Interconnect (QPI) and its integrated memory controller for enormous memory bandwidth. As Ars Technica's Jon Stokes puts it, "What this means is that Intel no longer has to equip its processors with freakishly large unified caches designed to mitigate the effects of the bandwidth starvation with which Intel platforms currently struggle."

Indeed, the quad-core Nehalem CPUs that Apple is using have relatively tiny level 2 (L2) caches - just 256 KB for each core. This is coupled with a shared 8 MB L3 cache that's built right into the CPU, so no more delays getting data from a separate, slower, external cache.

The Nehalem architecture is designed to keep the cores fed with data rather than wasting cycles waiting for data. Because of this immense bandwidth, each core can do Hyperthreading, which make it act like two separate cores. That means even the most affordable (still $2,500!) Mac Pro can process 8 threads concurrently. (This is a technology Intel last used in the ill-fated Pentium 4.)

Apple has been optimizing OS X for a multi-processor, multi-core world so that operating system is aware of its resources and knows when it makes more sense to use multiple cores on a single CPU or one core each on multiple CPUs. With Hyperthreading, there is the additional option of having a single core handle two threads. Each strategy has its benefits and drawbacks.

Only in recent years have we seen personal computers with multiple multi-core CPUs, and only now has Hyperthreading been added to the mix. In the old days, the OS didn't worry whether two cores were on the same CPU or different ones; now it will be able to choose the most efficient mix of threads, cores, and CPUs.

Intel has added new instructions to SSE 4.2 that are designed to improve string handling, particularly XML, which makes the new architecture even more Web-friendly.

Finally, Nehalem has Turbo Mode. When all of the cores aren't being used, the CPU can overclock the core(s) in use to improve performance. In the case of the 2.93 GHz Mac Pro, Apple states that it can reach 3.3 GHz in Turbo Mode.

In brief, all of this means a lot of processing power. Tom's Hardware benchmarked a 2.93 GHz Nehalem and compared it with a 2.93 GHz Core 2 Extreme X6800 and found Nehalem was 29% more powerful - and that was using a motherboard that wasn't optimized for Nehalem. Expect more from Apple.

When all is said and done, we may see anywhere from a 25% to 33% performance increase GHz for GHz, which would make the 2.66 GHz 8-core 2009 Mac Pro more powerful than the 3.2 GHz 8-core 2008 Mac Pro. Apple has a right to call this "the fastest and most powerful Mac ever."

For those who don't need this much power, the new iMacs use a traditional Intel Core 2 Duo CPU.

There's More

Apple has designed the new Mac Pro for easy access and easy upgrades. The three PCIe slots are readily accessed when the side of the computer has been removed, the board holding the CPU(s) and RAM slides out, making it easy to install additional RAM, and the hard drives slide into their drive bays.

Apple has eliminated FireWire 400 across the board, but the Mac Pro more than makes up for that with four FireWire 800 ports (all you need to use FW 400 devices is a FireWire 800-to-400 adapter or cable). There are five USB 2.0 ports, and two separate gigabit ethernet ports.

Nvidia GeForce GT 120 graphics round things out, and the ATI Radeon HD 4870 is available as a $200 option.

Overall, the new Mac Pro should run circles around the old one. We look forward to seeing the first benchmark results.

Value: 2008 vs. 2009

We haven't seen much in the way of clearance prices on the 2008 models. The 2.8 GHz 4-core is available for about $100 less than the best price of the new 2.66 GHz 4-core model, but with everything going for it, the Nehalem model is the hot buy.

If you want an 8-core Mac Pro, however, the close-out 2.8 GHz model is available for about $2,600. That's $600 below the best price on the 2.26 GHz 8-core Nehalem machine. That's also just $200 more than the best price on the 4-core 2.66 GHz Nehalem model, so it should sell quickly at this price.

There are so many options and so much is new, that it's difficult to know just what to make of the overall value equation. Yes, faster CPUs and more cores will provide a lot more power, but I think we've reached the point where the entry-level models offer all the power that most users will need almost all of the time.

If you'll never need more than 8 GB of RAM, the 2.66 GHz quad-core Mac Pro is a lot of power at $2,400 (after mail-in rebate). If you need more RAM or more processing power, the 2.26 GHz 8-core Mac Pro will let you install 32 GB of RAM while providing about 70% more power - but at a $3,200 (after rebate) price tag.

Frankly, being low-end users, we can't really fathom the kind of power these machines have, but if you need more power than the iMac can offer, this is where you'll find it.