One Brain or Two?

This article was posted about three weeks before Mac OS X 10.0 first shipped, so it reflects the reality under Mac OS 9.1. OS X has far better multiprocessor support, which Bare Feats demonstrates in an October 2001 comparison of single- and dual-processor G4 Power Macs using OS X 10.1.

Remember last July when Apple introduced the dual-processor "Mystic" Power Macintosh G4 with the slogan "Two Brains Are Better than One"?

Remember January 2001, when Apple replaced those with mostly single-processor models?

The 2001 "Digital Audio" Power Mac G4 offers some real advantages over the 2000 models: a 133 MHz system bus, AGP 4x video, the Nvidia GeForce2 MX video card, CD-RW, faster CPU speeds, and even the option of burning your own DVDs. There are even two different G4 processors - the 7410 in the 466 and 533 MHz models and the more powerful 7450 in the 667 and 733 MHz machines.

But is one 733 MHz brain better than two 533 MHz brains?

That's the question Rob Art Morgan at Bare Feats, along with a lot of other Mac users, has been wondering. Now that the G4/733 is available, Rob Art has been busy benchmarking it against the lone dual-processor configuration Apple currently offers, a Power Mac with twin G4/533 processors.

So far, the results are mixed - but looking at the price difference, a clear winner emerges.

The Tests

The first two benchmarks use iMovie 2.0 to create a title effect and export a 46 second movie. As expected, the G4/733 handily outperforms a single processor G4/533, but the dual 533 goes on to edge out the 733. The difference is even more pronounced when exporting the movie. Despite a lower price, the dual 533 wins both tests.

For the third benchmark, Rob Art rips three Beach Boys songs. The dual 533 wins this comparison by an even bigger margin.

Benchmark 4 is rendering a 3D logo in Cinema 4D. In this comparison, a single processor G4/533 beats the G4/733. The dual 533 configuration is roughly twice as fast as the single G4/733.

Benchmark 5 runs 20 actions within Photoshop and probably better approximates what top-end G4 users will be doing at work. The single CPU 533 runs these actions in 92.5 seconds, the 733 trims that to 85, and the dual 533 strips the time down to 66.6 seconds. That puts us at 5 of 5 for the dual 533.

Gamers will find the next two benchmarks most interesting. Running Quake3Arena at 1024 x 768 and "maximum," the G4/733 with the Nvidia GeForce card edges out the dual 533 by almost 3 frames per second. Interestingly, a dual G4 configured with an ATI Radeon card outperforms that. Still in the default configuration, the G4/733 finally won a test.

The second gaming test is Unreal Wicked 400, again run at 1024 x 768 and "maximum." The G4/733 edges out a small win over the dual 533, but the dual 533 with Radeon smokes both. Still, the 733 MHz Mac wins its second benchmark, giving it 2 wins out of 7 tests.

Bare Feats may post more results. Stop by regularly to find out. Rob Art and his crew run some of the most interesting head-to-head comparisons on the Web.

The Value

Performance is wonderful, but Low End Mac has a greater interest in value. At my last job, we never ordered the fastest Macs, because dropping back one or two levels provided excellent performance and a much more attractive price.

We also have a very practical perspective on things and believe that once you get past a G3/300 machine, most users most of the time will be pretty darned happy with their computer. In today's MHz sweepstakes, we keep wondering why anyone needs more than 400 MHz. We're thrilled with our PowerBook G4/400 - and the money we saved compared with the far more costly 500 MHz model.

Today we'll compare the third and fifth values on the Power Mac G4 page at the Apple Store.

• Dual 533, 1 MB L2 cache, 128 MB RAM, 40 GB drive, CD-RW, GeForce video, 56k modem, $2,499
• Single 733, 256 KB L2 cache, 1 MB L3 cache, 256 MB RAM, 60 GB hard drive, CD-RW (not SuperDrive), 56k modem, $3,099

Not exactly comparing apples and oranges. Part of the US$600 difference comes from more memory and a larger hard drive. Since Apple won't sell the 733 with less than 256 MB RAM or that 60 GB drive, we'll make the dual 533 match:

• Dual 533, 1 MB L2 cache, 256 MB RAM, 60 GB drive, CD-RW, GeForce video, 56k modem, $2,799

Of course, in the real world you'd be smart enough to buy memory anywhere but Apple, wouldn't you? A quick visit to ramseeker shows you could buy two or three 256 MB sticks of PC133 memory for the $200 the Apple Store ads to bring you from 128 to 256 - you do the math!

Assuming you pick up the memory for about $80, here's the deal.

• Dual 533, 1 MB L2 cache, 256 MB RAM, 60 GB drive, CD-RW, GeForce video, 56k modem, $2,679

You also have the choice between the stock Nvidia card and the ATI Radeon at the same price. If you're a serious gamer, you'll want to think through the options here.

The Value Equation

The dual 533 won five of seven benchmarks; it was edged out in two. Similarly configured to the CD-RW version of the G4/733, it comes in at $420 less, a saving of almost 16%.

With OS X due out in less than three weeks with full multiprocessor support, at least comparable performance for dual 533, and the option of saving over $400, the "two brains are better than one" models looks like the no brains choice for performance and value if you need top-end performance.

If you don't need that level of performance, we'd steer you to the single-processor G4/466, which you can pick up for as little as $1,649 if you don't need a 56k internal modem.

It's too bad the SuperDrive isn't an option on the dual 533; it would really give the $3,499 G4/733/DVD a run for the money.

Of course, this isn't the end of the story. As Motorola ramps up production, we may well see dual 733 machines.

And some people will claim that Bare Feats benchmarks put the new 7450 processor at a disadvantage, since the programs and Mac OS haven't yet been optimized for the extra integer and AltiVec units in the new CPU (see our guide to PowerPC processors for more on that).

Of course, if you buy the computer today, you don't have those optimized programs, either.

We're not buying - we're just thrilled with our Titanium PowerBook - but if we had a reason to buy a high-end production machine, we'd give the nod to the "two brains are better than one" dual-processor Power Mac G4/533.

Links

• Which is faster, G4/733 or dual G4/533?, Bare Feats
• The Apple Store, compare pricing for your configuration
• ramseeker, which we always check before buying memory