About the New Format: Starting with this review I've decided to change the way performance tests are shown. Instead of a long comparison list or several graphs of performance test results, I've designed a single relative performance graph, or gauge if you will, of how this product compares to the average performance of a range of similar upgrades and Apple G3 systems. This will allow easier 'at a glance' indications of how the product under review compares in all test categories. Below the graph will list model specifications and compatibility information including OS X (server for now) compatibility. I hope you find this format easier to digest.

XLR8 was the first company to ship a 400MHz G3 CPU card upgrade to my knowledge (the outstanding G3 400/200/1MB CPU card slot model reviewed here last fall). As with that model, I saw very reliable operation and plug and play installation with this upgrade during the entire review period.

If you're new to CPU upgrades, or have not owned a pre-G3 Apple or Mac clone, the ZIF upgrades for Apple's G3 Macintosh models are generally free of the compatibility and bus speed issues that often complicated older Mac CPU upgrades (see the FAQ and CPU Reviews page for more details).

Installing the Zero Insertion Force (ZIF) socket upgrade is accomplished in a few minutes. Since bus speed is fixed by the Apple jumper block (G3-ZONE has details), there is only one adjustment setting needed - System Bus to CPU ratio. Select the proper ratio as shown in the XLR8 manual according to your G3 card model and system. The different bus speeds of the Apple G3 systems require different CPU/Bus ratio settings.

For example, the beige/AIO G3 has a 66Mhz system bus, the B&W G3 has a 100MHz bus. This means that B&W G3 CPU speeds must be a multiple of 50Mhz, so the proper setting for a 400Mhz CPU speed would be a 4:1 Ratio (100Mhz bus speed x 4). The 66MHz bus speed of the beige/AIO G3 allows selecting smaller increments of bus, cache and CPU speed (33Mhz steps) than the B&W G3 (50Mhz steps).

Note: Attempts to run faster than rated speeds in the Blue and White G3 were not successful with this particular sample. The XLR8 cache control refused to allow a faster than 2:1 (200Mhz) ratio to be set, reporting that the cache would not be reliable at that speed based on its automatic cache test.

When the ZIF was set to a 4.5:1 (450Mhz) bus/CPU ratio setting (50Mhz over rated speed), the B&W G3 refused to boot. Since the beige G3 has a 66Mhz system bus (and therefore 33Mhz increments of CPU/Cache speed), it is possible it may have run 433Mhz in that system. To see what other XLR8 owners reported and rated this upgrade, use the search function of the Rate Your G3 Card database (select XLR8 as the brand and Apple Beige or B&W G3 as the Mac model). My search at the time of this review found a report of 434Mhz/187Mhz from this same XLR8 model in a beige G3.

For a guide to installing a ZIF upgrade, see the installation/docs page my PowerForce G3/400 ZIF review.

The XLR8 G3 400Z ZIF review sample contained an IBM 400MHz CPU, copper as expected, verified by our PPC Checker (other samples may contain Motorola models). The CPU/Bus ratio adjustment is done via jumpers similar to those on the motherboards of the Apple G3 systems. Ratios of 3.5:1 to 8:1 are provided (of course only a very small subset of these will be reliable, in the B&W G3, only one). Although not as easy to adjust as the rotary switch on the PowerLogix ZIFs, since you will only change the setting a few times at most (if you explore faster speeds), this is really a small nit.

There are two reasons I prefer an adjustable ZIF model; it allows the upgrade to work at the proper CPU speed in Beige/All In One (AIO) and B&W G3s (different bus speeds, therefore different ratios are required) and it also allows experimenting with higher CPU speeds (potentially risky, but rewarding in some cases).

Compatibility Tests:

Although generally ZIF upgrades are free from the compatibility issues that have been present in the CPU slot upgrades for older Macs (resolved now in some cases via software), I verified the XLR8 400 had no problems with the following hardware and software that had been incompatible with some older Mac upgrades:

• Adaptec 2940UW, 2940U2W PCI SCSI cards and wide SCSI drives
• Retrospect backup software

In addition, I performed a complete OS X Server install successfully (including verifying the cache was enabled - see the FAQ for details on how to do this). During the entire review period (several weeks of daily use), there were no problems or errors of any kind.

Performance Tests:

All tests were done with my 'working' (not trimmed, but no Speed Doubler, Libmoto or other 3rd party extensions). Quicktime 3, PC exchange and the Rage128 1.0 driver update were installed. Graphics mode was 1024x768, thousands colors, 75Hz. Virtual memory was off. The Blue and White G3 was running OS 8.5.1 of course.

The following performance graph shows how this upgrade compares relative to a range of Apple G3 systems and/or similar (ZIF) upgrades.

Since this sample would not run beyond the rated speed, and due to the fact literally all ZIFs of the same speed/cache size perform identically, the graph contains no surprises, except for slightly better than average Photoshop 5 performance (over my B&W G3's stock CPU running at the same speed). To compare these scores to other systems/upgrades in more detail - see the other CPU Card Reviews,B&W G3 Performance, Photoshop 5 Performance and G3 Apps Tests pages. (These links will open in a separate window to allow comparisons without paging back and forth.)

Maximum temperature seen during the testing was 27C (as reported by Powerlogix's Speedmeter), but as I've mentioned before, I do not believe the temperatures reported by software utilities on the 333MHz and up G3 CPUs are accurate. Common sense says that the internal junction temperature of a 400MHz integrated circuit should be much higher than the ambient room temperature.

Game Performance in the B&W G3:

The Video card or driver/software has to be either saturated or there is some other bottleneck, since even a 550Mhz CPU has literally identical scores. For other Blue and White G3 results - see my Yosemite Game Performance page.

Documentation:

The XLR8 manual was one of the better ones I've seen recently, with glossy stock cover and well illustrated. Clear, professional quality line drawings covered installation and speed settings. My first revision was written before the Blue and White G3 was released, but the installation drawings and explanatory text was the clearest I've seen on the procedure. Chapters on cache control software and troubleshooting were also included. Documentation was the best I've seen so far.

Software:

XLR8's v1.3 cache control software is one of the best on the market, with automatic cache speed setting (with manual override that detects if the cache can support the selected speed).

XLR8 Cache Control v1.3

Clicking the image above will take you to XLR8's cache control page with an illustrated guide to the available options and settings. Generally, you won't have to change anything as the automatic settings were optimum in my tests.

Review Sample Hardware Specs:

• IBM 400MHz PowerPC 750 (Copper) PPC750L-DB0A400
• 1MB L2 Backside Cache (2x Galvantec GVT71128G36T-3 SRAMS)
  
• Selectable Bus/CPU Ratios of 3.5:1 to 8:1 in .5x steps
• Fits: Apple beige G3/B&W G3/All-in-One G3
• Max Speedmeter Temp Seen: 27 degrees C
• Maximum Speeds Reached: 400/200 (B&W G3)

With the XLR8 design, there was plenty of clearance in the B&W G3 to fit the ZIF in the socket with the ATI Rage128 card installed. Some other models are often a very tight fit due to adjustment knobs. Adjustments in CPU/Bus ratio are easily done with the ZIF in place, unlike the PF 466 ZIF which had an rotary switch partially covered by the edge of the Rage128 card in the B&W G3.

Summary:

Although I was unable to run this sample over the rated speed in the Apple Blue and White G3, I suspect it may have run 433Mhz in a beige G3. I liked the fact I could run the cache enabled without adding additional software, the excellent compatibility (OS X/Adaptec/Retrospect) and the excellent documentation. With prices dropping frequently, this could be a very attractive upgrade for beige and even B&W G3/300 owners.

Pricing/Availability:

At the date of this review (mid April 1999), XLR8's price list showed a suggested retail price of $729, but upgrade prices often drop drastically. At this time site sponsor Bottom Line listed the card for $699.99, as did MacGurus. Other World Computing did not have XLR8 ZIFs available per their search engine at this time.

Test System:
The base system used for this review was an Apple B&W G3/350/DVD with the standard array of extensions (no trimming done). System details are listed below.

System Hardware Summary:

• Apple B&W G3/350/DVD (Yosemite):
• 192MB RAM (stock 64MB DIMM, one 128MB DIMM)
• Stock 6GB IDE Hard Disk (40% full, not defragmented)
• Maxtor 10GB IDE Slave Hard Disk (70% full, not defragmented)
• Adaptec 2940U2W with U2 Cheetah & U2 Atlas III drives
• DVD/CDrom drive (DVD option)
• OEM IDE/ATAPI ZIP drive (slave on CDrom IDE channel)
• Stock ATI Rage128 card with 16MB SDRAM (driver update 1.0)
• Game Wizard 12MB Voodoo2 card (only PCI card installed)
• OS 8.5.1, 6MB Disk Cache, VM off, QT 3.0, QD3D 1.5.4, etc. [No Libmoto]

Reviews of Similar Upgrades:

• PowerForce G3 466/311/1MB ZIF
• PowerForce G3 366/183/1MB ZIF
• PowerForce G3 400/266/1MB ZIF
• First PF 333 ZIF Prototype

Don't forget to check out the Rate Your G3 Card searchable database (including PowerBooks, Nubus, L2 Cache slot and ZIF models). Over 1050 owner reports and growing daily!

If you're not already done so - it only takes a few minutes to Rate Your G3 Upgrade card.

Got Questions? Check the Answers to Frequently Asked Questions (FAQ) page, a Topic oriented database with over 200 answers to common questions on Upgrades (old and new Macs), Video cards (3dfx and otherwise), memory, displays and much more.