Eight-Core Mac Not for General Tasks

Buying an eight-core Mac Pro featuring two 3GHz Quad-Core Intel Xeon chips will cost you roughly US$700 more than a single quad-core 3GHz machine. Yet, all that extra processing oomph will net you only a 4-percent performance boost in Speedmark 4.5, Macworld Lab's standard benchmark suite.

So does that mean the $3,997 eight-core Mac Pro announced in April is a bust? Not hardly--rather, it's more a case of this being a desktop better suited for different tasks than our tests typically measure.

As many Macworld readers know, Speedmark looks to quantify the performance Mac users can expect when running typical real world tasks using typical applications such as Microsoft Office, iMovie, iTunes and OSX finder applications. That's a perfectly acceptable battery of tests when dealing with Apple's standard offerings--MacBooks, MacBook Pros, iMacs, and even the standard Mac Pro configuration. An eight-core Mac Pro, however, does not fit into that crowd.

Rather, this Mac Pro configuration uses a pair of Clovertown 3GHz Quad-Core Intel Xeon 5300 series processors, not to mention 8MB of L2 cache per processor, 1.33GHz 64-bit dual independent frontside buses, and the capacity for 16GB of main memory. It's a machine that thrives when running applications that are optimized to take advantage of multiple cores. And while we include some higher-end tests like rendering scenes in Cinema 4D, using Compressor to encode some DV footage and running a Photoshop action script, these performance-hungry applications are in the minority in our test suite. Thus, the overall Speedmark score for the eight-core Mac Pro suffers.

If you spend most of your day researching articles on the Web, tinkering with Excel spreadsheets and writing e-mails, this is definitely not the system for you. And that shouldn't be a surprise--after all, how can you expect Microsoft Office to make efficient use of eight processing cores when it doesn't even work natively with the chips in an Intel-based Mac? In fact, the 2.5GHz Power Mac G5 leaves all the Intel-based Macs in the dust in our Microsoft tests.

But that's not to say that the eight-core Mac Pro doesn't have its constituency. If you spend you time rendering 3-D scenes in an optimized application like Cinema4D, these eight cores can crank out a result 44-percent faster than the 4-core system and 53-percent faster than the Power Mac G5. Compressor scores on the 8-core can also be very impressive, depending on the task. The test we usually run involves converting six minutes of video using MPEG 2; however, we didn't see a big boost between the four- and eight-core machines. When we brought these results to Apple's attention, company representatives suggested trying some other codecs, such as H.264. Using Compressor 3's presets for converting to H.264 for Apple TV, we saw speeds go from 9:13 on the four-core to 7:43 on the eight-core, a 16-percent improvement. A quick test with extra RAM failed to make much of a difference in these results.

Apple agrees with our findings about routine tasks involving Office, e-mail, and Web browsing: This eight-core system is not meant for the general consumer. Rather, Apple describes its eight-core Mac Pro as one of those instances where the hardware is meant to push the software -- Apple hopes that this eight-core machine will help developers of high-performance applications optimize their software for multi-core systems. We hope so too.

Check back for our full review, including more tests including a multitasking suite and tests with additional RAM.

[James Galbraith is Macworld Lab director.]


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