September 3rd, 1997

SEPTEMBER 3rd, 1997


Features BRYAN CHAFFIN
([email protected])

The Fastest Computer You'll Never See

Webintosh Labs awaited with great glee the arrival of The Beast. The PowerTower Pro G3/275 with the first public appearance of the PowerPC 750 (code named G3 and Arthur) and it's backside 1 MB level 2 cache will be legends in their own time. Or they would be if they were ever to be released. They will not.

The most important aspect of this machine is that it is fast. The PowerTower Pro G3 screams so fast, it generates its own Doppler Effect. Our system was configured as follows:

    275 MHz PowerPC 750
    1 MB Level 2 Backside Cache
    4 GB Ultra-SCSI HD
    128 MB RAM
    24X CD-ROM
    128-bit IMS TwinTurbo Graphics Card with 8 MB of VRAM
    Internal Jaz Drive
    Internal ZIP Drive

This is not your father's Macintosh.

We put the machine through its paces utilizing MacBench 4.0, Photoshop 4.0. We also wanted to see how it fared with such day-to-day fare as Netscape Communicator and Cyberdog. Virtual PC rounded out our real world tests leaving the all important Quake and Marathon Infinity to test the entertainment value of The Beast.

The MacBench results were quite phenomenal. MacBench 4.0 uses the PowerPC 601 based 60MHz PowerMac 6100 as the benchmark standard. Webintosh Labs also chose the results of the PowerTower Pro 225 as a more realistic source for comparison in addition to the benchmark results.


    Test Results
    See just how loud the PowerTower Pro G3 screams in the MacBench 4.0 benchmark tests.


The 275 MHz 750's results in comparison to the 225 MHz 604e's results:

    Processor: 132.3% Faster
    Floating Point: 27.3% Faster
    Disk Mix: 56% Faster
    Graphics: 17.6% Slower
    Lo-Res Graphics: 17.4% Slower
    CD-ROM: 101.9% Faster

The processor's speed is simply unbelievable. This system more than doubles what was the fastest desktop system only a few short months ago. While much of this increase can be attributed to the 1 MB Level 2 Backside Cache, the chip itself deserves a high degree of respect. The 750 is an amazingly small chip that draws only 5 watts of power. The heat sink used for the system is approximately 3" x 1", a very small size indeed when compared to the mammoth sinks used in Pentium and Pentium II systems. The PTP does make use of 3 fans, though even with these, the system is as quiet as a Power 100. When these chips make their way into laptops, the world of computing will be in for another paradign shift (Joel Kocher, former President of Power Computing, demonstrated a 750 based laptop that were ready to ship. Apple would not certify the system.).

The floating point speed increase is much less than that of the processor increase. The 750 was not designed to be a floating point power house, that role is filled by the Mach 5 chip chosen by Apple for their new generation machines. Still, a 27% increase is remarkable and made its presence known during our Photoshop tests. The lack of comparable floating point performance was supposedly necessary to achieve the Backside Cache, a feature that the Mach 5 does not have.

The Disk Mix is equally impressive turning in a 56% gain in performance. This is due to the Ultra-SCSI 3 Adaptec card and the hard drive itself, a 4 GB SCSI 3. This SCSI 3 system was the second most readily noticeable area of improvement as download and installation times were quick enough to make us feel that the process had crashed on more than one occasion. Transfer rates from, and to a lesser degree to, the Zip drive were also speedy.

The graphics results really surprised us as they showed a marked decrease in performance. What is most puzzling is that both systems use the same video card, the IMS TwinTurbo 128-bit 8 MB card. With the increase in processor performance, we expected the graphics results for the PTP 275 to be a touch speedier than its little brother's. We repeated the tests using different system configurations to see if there might be an unusual extension combination affecting the tests, but all test runs gave us approximately the same results. Our test unit was a prototype that might not be as properly optimized as the final product would be. On the other hand, the entire product line was due to ship in a short while and should have been optimized already.

The CD-ROM results were excellent, but not surprising considering that the drive is a 24X speed drive. Installations from a CD were very fast, though the drive itself was a bit louder than expected.

After completing the battery of MacBench tests, we put the machine through our own real world tests. Combining Photoshop 4.0 with the default desktop images that ship with Mac OS 8, we performed .3 degree rotations, Gaussian blur, texturizing effects, and a host of Kai's Power Tools filters. All of these filters were completed in mind numbingly fast times. In fact, we only had progress bars brought out on two of the ten filters we used for this test. The images we used were all a little bit over 1 MB in size. Photoshop has always been fast on a Mac, but these results would very likely offer the opportunity for a marked increase of productivity in many graphic houses.

One surprising area of increase was that of browser performance. For the test we used Communicator 4.01a. We tested ted the PTP 275 on a 128k ISDN connection to the Internet. Pages were downloaded and rendered in a snap compared to slower machines on the same connection. Large files saw some of the fastest download times we have ever seen. Much of this performance may be attributed to the Ultra-SCSI 3 hard drive. Cached pages in particular saw reload times almost as fast as Cyberdog or MSIE even when compared side by side.

Webintosh has already reported that Cyberdog has finally realized his true destiny with Mac OS 8. On the PTP 275, this destiny is fulfilled even more. There are simply none of the slowdowns normally associated with Cyberdog. In fact, all OpenDoc application we tested really rocked on the PTP 275.

Virtual PC has offered a lot of promise to those in the Mac world who are sometimes faced with running a PC application "or else." This becomes especially true in light of the effective curtailment of cloning by Apple. As Macs simply don't get any better than the PTP 275, we wanted to see how Virtual PC could be at its best. We are sad to say th at it is not so good. We allocated 65 MBs of RAM to the program which then does the RAM optimization itself. Using Norton's SYSINFO to gauge clock speed while in DOS mode, we were told we were running a Cyrix 586 at 201 MHz. Before you get excited, that's about as fast as a Pentium 100. While this is very serviceable, it is nowhere near the results reported at the WWDC by Connectix in their demo. It is a major dissapointment that the fastest Mac runs Virtual PC at approximately Pentium 100 speeds. Video performance was also fairly poor, especially with screen redraws. There was a noticeable lag in navigating the Windows 95 hierarchical menus. All in all, we were disappointed in these results. It is possible that with additional tweaking of the controls and settings, we would have seen better performance. Our guess is that it will take subsequent releases of Virtual PC to really see good performance. Connectix has already promised that many of these areas will be addressed in upcoming releases of Virtual PC.

Then there is MacQuake. It performed awesomely on the PTP 275. We tried a variety of screen resolutions and anything up to a full 640x480 ran perfectly smooth. Literally. There were no frames dropped at all. The motion was smooth and the level of detail extraordinary. At full screen resolution in 800x600 mode, we saw a noticeable drop in performance. The level of detail was still fantastic, but we experienced noticeable frame dropping. Most of the PC users who saw this demo were truly impressed.

Playing Marathon Infinity was also a dream come true. We ran it as high as 3/4 screen resolution in 800 x 600 mode with millions of colors and the movement was perfect. Anything higher required us to drop down to thousands of colors in order to keep the same excellent movement. This machine is a Mac gamers dream come true, even with the lack of on board 3D acceleration. We fully realize that the price of this machine effectively puts it out of the reach of most Mac gamers.

Now the sad part; this machine will never see the light of day. Apple has said that there was an incompatibility with Mac OS 8 with the PowerPC 750 processor, and that they would not certify it. We ran the PTP 275 for three straight days on Mac OS 8 and only experienced one system crash, and that involved the notoriously unstable Communicator. It was the most stable machine we have seen since the days of System 6.

Initially Power had announced it would ship the PowerTower Pro's without certification, but as details of the Apple buy-out of Power's Mac license began to solidify, Power backed down from this rebellious position. Now that Apple owns this technology, expect to see the incompatibility issue dropped as it was just a smokescreen to keep Power from releasing a machine that eclipsed Apple's offerings. If we are lucky, the best thing that could come out of Apple's cowardly Power buy-out will be that the Power engineering team will remain mostly intact and go to work for Apple. We could also see Apple use part or all of the specs for the 750 based PowerTower Pro's in it's own line of PowerMacs. Should this happen, it would be a good thing as this is the Fastest (and best) computer you will never see.

Bryan Chaffin can be reached at [email protected].

The Mac Observer Labs enjoyed the assistance of Dave Hamilton and Jeff Kievlan of Computer NERDZ! for technical matters related to this test. Webintosh appreciates their help.