Well, this has been an interesting summer/fall for Apple. I've been looking out for a possible upgrade/replacement for my PowerMac 450Mhz tower, but haven't seen anything that really appealed to me.

Back in August Apple released their newest round of PowerMacs using the new "wind tunnel" case with CPU speeds up to dual 1.25Ghz processors. While a combined 2.5Ghz of power might seem competitive to Intel's latest round of 2.8Ghz chips, that's really only true for applications that run multithreaded, and allow the operating system to distribute the workload between both CPUs. So, the general consensus in the user community to this release was pretty ho-hum, and that this was pretty much an interim box. Also along about this time, users became of aware of IBM's getting ready to release a new desktop PowerPC CPU based on its extremely powerful POWER4 server processor. This excited those users aching for more speed and tired of being put upon by the Wintel community. As the fall progressed, it became increasingly clear that IBM was building this chip for Apple. In addition to full standard compatibility with Apple's current crop of PowerPC chips, it also included a powerful vector-processing unit fully compatible with Motorola's Altivec unit. Since no one else uses a PowerPC chip with such an enhancement, Apple had to be the customer.

Topping it off, the new IBM chip is a 64-bit chip, compared to the current 32-bit chips in use in the user community. While this wouldn't provide any speed advantages, it would permit the computer to address a huge amount of additional memory in the future, far in excess of today's needs. So, this was clearly a chip for the future.

Thus, my quandary... The dual Motorola G4s in the newest PowerMacs are old technology, clearly near the end of the line for this design. Nothing remotely encouraging has come out of Motorola for a couple of years. Now, here's IBM getting ready to release a next generation chip. If you're in the market for a new high-end Mac, what do you do?

Alongside this hardware technology situation, Apple has been buying up high-end media software companies over the last year and a half. The concern was that the Motorola generation of processors didn't really have the horsepower to take advantage of this upscale software. So, what was up?

It became pretty clear that Apple was getting ready to move out with substantially more powerful hardware, but the timeframe was unclear. Last month, on October 15, IBM formally announced its new 64-bit PowerPC 970 processor based on the POWER4 server CPU at the annual Microprocessor Forum in Silicon Valley. During this presentation it also noted that the processor wouldn't be in full production until the second half of 2003, so now we're looking at the Macworld New York summer timeframe for an Apple announcement. What's Apple going to do between now and then?

Concurrently, we're now also beginning to hear stories about Motorola finally getting around to putting out a new G4 7457 processor (today's G4 Macs use the 7455 chip). So, the expectation currently is that Apple will be announcing new PowerMacs based on the new Motorola 7457 chip in January, following on with the new IBM 970 chip in the summer in its higher-end models. This helps a lot, if true, and returns me to my current situation.

I currently use a 2000-model PowerMac running at an ancient 450Mhz. It's a good machine, but not as peppy as I'd like with MacOS X running on it. However, I'm now also aware of the likely upcoming refreshes in Mac technology. So, when do I next buy? Being retired, I can no longer afford to just jump on the latest technology speed bump whenever it occurs. Whatever I buy has to be able to handle the upcoming software for the subsequent two or three years following its release.

Since a Mac based on the upcoming IBM 970 CPU seems to have the most potential, and it's nearly a year away, that turned me to checking out the possibility of installing a replacement CPU in my current Mac. Currently, two companies offer faster CPUs for my Mac, PowerLogix and Sonnet. I'd used a PowerLogix accelerator in my old Quadra 700 when I upgraded it to a PowerPC chip back in the mid-90s, and it worked just fine. So, I decided to check out the offerings from each company.

Both currently offer accelerators for my Mac using Motorola's G4 7455 CPU running at 1Ghz. PowerLogix also offers one with dual 1Ghz CPUs, but it's much more expensive. With Apple offering a dual 867Mhz CPU PowerMac for around $1700, it didn't make much sense to consider $1200 for PowerLogix's dual offering. So, I focused on the single CPU accelerators both offered for around $700.

Both companies have taken the approach of creating a single daughter card that simply replaces the daughter card Apple plugs into the Mac's motherboard. PowerLogix designed its card to accommodate dual processors, to give it both options. Sonnet's card only handles one CPU. PowerLogix also designed a new heat sink with fan to replace the standard heat sink that Apple uses. Sonnet has you simply attach Apple's heat sink to the replacement daughter card. PowerLogix also required that you run a program to install some software to turn on the 2MB cache on the card, whereas Sonnet made its card self-configuring.

So, in practice which approach is best? I decided to wait until both cards were out and read about user experiences before making my decision. PowerLogix was first out the gate, with Sonnet following in late October. I turned to xlr8yourmac.com on the web to check up on user CPU upgrades experiences, and was glad I did.

It appears that Wake From Sleep is a common issue with the PowerLogix solution. While a couple of Sonnet users have also experienced this problem, it's much less of an issue. With MacOS X, this was very important to me, since I seldom shutdown my Macs anymore, preferring to just put them to sleep so I can press the space bar and have full functionality again in just a couple of seconds. A second concern I had was the complexity of the PowerLogix setup. PowerLogix has you (1) replace the daughter card, (2) replace the heat sink and plug it into a power connector, and (3) run a command from the Terminal command line to activate the L3 cache on the card. Sonnet just has you replace the Apple daughter card with theirs, reattach the Apple heat sink, and you're done. While PowerLogix's steps are simple to implement, it gave me pause about their company's mentality. If it weren't necessary to make the user take unnecessary steps, why do so? We're Mac users, after all, and user-friendliness is our mantra. I much preferred Sonnet's philosophy of thinking the whole problem though for you and coming up with the auto-configuring card.

So, any other concerns? PowerLogix and Sonnet both seem to be having problems with their 800Mhz accelerator cards, so I'm glad I went with the 1Ghz version. PowerLogix is also having problems with their dual 1Ghz cards, judging from the problems some users are reporting. Additionally, in reading about PowerLogix's comments concerning the Wake From Sleep issue, I'm also not sure PowerLogix has accepted full responsibility for this issue. Sonnet seems to be taking a position that if the cards have a problem, they'll replace them.

Well, as you've guessed, I went with Sonnet. Whenever I have a choice, I go with simplicity, to hopefully improvement reliability over the long-term, and I really preferred their customer satisfaction position. How about performance?

I ran Unreal and Unreal Tournament's timedemo 1 (press command-~ after starting game application, but before starting actual game, type timedemo 1 at prompt, then command-~ again to clear screen and watch frame rate numbers; repeat to type exit to stop) options to check on frames per second for each game. I have an ATI Radeon 8500 in my PowerMac and with the old 450Mhz G4 only averaged 26fps in Classic. This doubled to 54fps in Classic (83fps in MacOS 9.2.2) with the 1Ghz processor. Unreal Tournament improved from 22fps with the old processor, to 38fps with the 1Ghz CPU (57fps in MacOS 9.2.2). In the Finder in MacOS X 10.2.1, everything was much peppier. When I ran the Altivec Fractal Demo application, it noted the G4's Altivec unit performance improved from a little over 1Gflop to 3.3Gflops (billions of floating point operations per second). So, this was a very satisfying upgrade.

One final note, the Sonnet accelerator only works with MacOS 9.2 and MacOS X 10.1 or better, so if you plan to use with a basic MacOS 9 or earlier configuration, be careful. It won't see the startup volume. That may also be the case if you're used to booting from a CD to run utilities (I've dealt with this by having multiple boot partitions on my Mac).

So, I'm set for another year, and looking yearningly for the next generation IBM 970 processor. Also, remember that no Macs purchased from Apple after January 1 will be able to boot up into MacOS 9, so if you need this capability and want a faster Mac, you'll either need to purchase a new Mac now, or look into the accelerator option.

- Dave Marsh

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