Accelerate Your Mac! - XLR8 MAChCarrier 450 10X G3 Review

Throughout this review I use the convention of showing CPU, Cache and Bus speeds (in MHz) in the format of CPU Speed/Cache speed/Bus speed, so 450/225/45 would mean a CPU speed of 450 MHz, a backside cache speed of 225 MHz and a Bus speed of 45MHz.

Unlike the vast majority of current G3 CPUs on the market, this particular G3 CPU is one of the new IBM 10X ratio (bus to CPU ratio) models. Previous G3 CPUs had a limit of 8X max Bus/CPU speed ratio - which means that your Mac would have to run at 50MHz bus speeds to allow a 400MHz CPU speed (bus speed 50MHz times 8X ratio = 400MHz CPU speed). Unless you buy a 10X ratio G3, remember max CPU speed you will be able to run is 8 times your Mac's reliable bus speed.

MacBench 5.0 was run on both systems used for the review - a loaded Genesis (based on a 9500 motherboard) and PowerComputing PowerCenter Pro. I've separated the PowerCenter Pro results to better illustrate the upgrade boost compared to the stock 210MHz 604E CPU card.

Remember that Macbench Graphics scores will vary depending on graphics mode and the installed video card. Since all these Macs have graphics cards of widely differing performance capability, this is not a reflection on the CPU card under review. All tests were done at 1024x768, thousands colors, with a 75Hz refresh rate. In Macbench 5.0 a 1000 score is the baseline based on performance of an Apple Beige G3/300 running millions colors, 1152x870. Consider this when evaluating the scores at lower resolutions and color depths.

See my notes below on disk scores and remember that disk performance will vary widely based on fragmentation, free space (outer tracks on the disk are fastest) and disk cache size set in the Memory Control Panel. Disk Cache settings boost MacBench scores up to a point (about 6MB or so) as noted in last year's Disk Cache Study.

Be aware that each card and system has some tolerance variation, so these speeds may not be attainable with every card/system/hardware combination. Due to the risks involved I do not recommend overclocking but do test for maximum speeds (called fmax) during my reviews. The specific CPU chip on each card, your motherboard components/installed hardware and RAM mix can affect maximum reliable speeds - never buy a CPU card assuming you will be able to overclock it or repeat anyone else's results (for instance reports in my Rate Your G3 Upgrade database). Consult the card vendor and your system dealer for warranty impacts from overclocking any product (required disclaimers apply).

MacBench 5.0 Tests: The two graphs below compare performance of the MAChCarrier450 in the Genesis system (against a B&W G3/400) and the PowerCenter Pro (against the stock 210MHz 604E CPU card).

Note: The Rage128 in the Blue and White G3/400 was installed in the 66MHz PCI slot. Also remember the Genesis is running less than 1/2 the bus speed and a 33MHz slower PCI slot (as well as a less advanced PCI controller) for the video card. Both systems had disks appx. 80% full and not optimized. Genesis used UW SCSI Cheetah 4.5GB drive with 4MB disk cache. B&W G3/400 used stock Quantum IDE 6GB drive with OS 8.6 default disk cache setting of 6MB.

The next graph shows the PowerCenter Pro performance gain. Note that I'm running the G3 card at the maximum speed I found reliable with that particular system/card/RAM combination - which is beyond the rated speed of the CPU so these results may not be repeatable in your Mac. In general only the PowerCenter Pro is capable of 60MHz bus speeds as that was the original motherboard design speed. Also note that I had to remove the stock L2 cache dimm to run this bus speed reliably (see the later pages of my 'Inside the PowerCenter Pro' review for inside details on that system)

I ran the BYTEMARK DR/3 test which is probably the most 'pure' CPU benchmark I know. I include it here for curiosity only, as I consider BYTEMARK the least indicative of all benchmarks as far as actual OS/end user performance. ByteMark is a small, synthetic benchmark and is highly affected by compiler optimizations (some tests on the PC with VisualC++ compiled versions show the PII scoring higher than the G3 for instance). I've included scores from a B&W G3/400 and some past CPU card reviews for comparison.

All scores listed are from G3 CPUs with 1MB of backside cache. Scores are rounded off to two decimal places. Speculative Processing was enabled for all tests except for the MAChCarrier450..