Power Macs deliver ample performance, with more to come
Tom Thompson
Apple missed the Mac's tenth anniversary by only two months when it introduced its new PowerPC-based computers, the Power Macintoshes, in March. Considering the hurdles the Power Mac design team faced, the schedule slip is forgivable. With the new Macs, the team had to implement the contradictory goals of supporting an existing base of CISC software that has built up over the decade and harnessing the throughput of the PowerPC 601 RISC processor (See "Apple, IBM Bring PowerPC to the Desktop," April BYTE). Not only that, but the new systems had to be affordable as well.
The results are embodied in three machines. The Power Mac 6100/60 system has the lowest price at $1819. (Prices are without monitor and keyboard.) It uses a Centris 610/Quadra 610
pizza-box chassis with a 60-MHz processor, a single 601-specific Processor Direct Slot (PDS) for expansion, and a 160-MB hard drive. An adapter lets the 6100/60 use a 7-inch NuBus board.
The midrange Power Mac 7100/66 inhabits a Centris 650/Quadra 650 chassis and provides a 66-MHz processor, one 601 PDS slot, three NuBus 90 expansion slots that can hold 13-inch boards, and a 250-MB hard drive. This system costs $2899. Finally, there's the ultimate power-user system: the Power Mac 8100/80. Based on the Quadra 800's successful mini-tower design, it has an 80-MHz processor, one 601 PDS slot, three NuBus expansion slots, and a 250-MB hard drive. It costs $4249.
The Power Mac hard disks may seem small compared to those in PC systems, but they're ample for Mac applications, which are typically far smaller than Windows applications. Also, the three systems come standard with 8 MB of RAM, built-in Ethernet, CD-quality (16-bit samples at 44.1 kHz) stereo sound, and on-board video that supports 16- or 24
-bit color, depending on the model.
The optional AV Power Mac system configuration is essentially a Power Mac with an Apple AV Technologies board in the 601 PDS. The option also includes an additional 8 MB of RAM for the 6100/60 and 7100/66 systems and an additional 16 MB for the 8100/80. You need the extra memory to support the voice-recognition and telephony software bundled with the AV system.
If you need to run the occasional DOS/Windows application, another Power Mac system configuration bundles Insignia Solutions' SoftWindows emulator. This configuration gives you SoftWindows and 16 MB of RAM. It also jacks up the price $300 to $800, depending on which Power Mac it is.
For owners of Centris 610/Quadra 610, Centris 650/Quadra 650, and Quadra 800/840AV systems, appropriate PowerPC logic-board upgrades are available. For other 68040-based Macs, a 68040 PDS accelerator board with a 601 processor and Power Mac ROMs ($699) will do the trick. Apple has announced that it will also offer Pow
er Mac upgrades for certain 68030-based Macs, but no details were available at press time.
Features and Compatibility
I received all three Power Mac systems for evaluation. Apple equipped each with an optional CD-ROM drive and an AV Technologies board. The Power Mac 6100/60 and 7100/66 came with 16 MB of RAM, and the Power Mac 8100/80 had 24 MB.
Two features stood out when I used the CD-ROM drive. First, the drive now has a built-in, motorized drawer that holds the disc, rather than that easy-to-lose caddy. Second, the systems readily boot from the CD-ROM drive. Formerly, you had to hold down the Command-Option-Shift-Delete keys to get a Quadra system to boot from its CD-ROM drive; now you just drop a bootable system CD into the drive and tap the power key. This is a handy feature for dealing with emergency disk repairs or installing new system software.
I copied my usual working complement of software to these systems and tried them out for several weeks. Software compatibility was re
markable, considering that all the programs were 680x0 CISC binaries now running on a RISC processor. Applications such as Adobe Illustrator 5.0 and Photoshop 2.5, Microsoft Word 5.1a and Excel 4.0, Claris MacWrite Pro 1.0v4, Aladdin Systems StuffIt Deluxe 3.0.6, and Freesoft White Knight 11.14 worked fine.
Even Control Panels and Extensions that heavily patched the 680x0 trap dispatch table continued to work, such as Adobe Type Manager 3.6, Now Utilities' Super Boomerang 4.0.1p and WYSIWYG Menus 4.0.1, Symantec's Suitcase 2.1.4, and Rock Ridge Enterprises' VideoBeep 1.05. In fact, some applications that run erratically--if at all--on most 68040-based Macs worked just fine on the Power Macs.
The systems' performance makes them naturals for graphics-intensive work. For example, Photoshop 2.5 did lightning edits on large 15- to 20-MB, 24-bit color TIFF files. The biggest performance boosts, however, will be seen in applications rewritten in native code. The question, of course, is how many native
applications will appear on the market in the next few months. I'll get back to that question shortly.
Insignia Solutions' SoftWindows 80x86 emulator ran a number of Windows applications reliably. The emulator doesn't support Windows' 386 enhanced mode, and it requires about 13 MB of RAM--hence the additional memory on the SoftWindows-equipped systems. The emulator mustered performance between that of a fast 386 and that of a 25-MHz 486SX.
Unfortunately, this sort of speed is barely adequate for demanding Windows applications. Running Excel 4.0 in SoftWindows to process some of the Power Mac test results just taxed my patience. If you need to run a Windows application once in a while, SoftWindows will do. But if you expect to use it often, you'll need the patience of Job.
Speed Demons
Benchmark testing showed that the Power Macs' performance when running 680x0 application binaries ranged from that of a 25-MHz 68030 to better than that of a 40-MHz 68040. The spread is wide because not a
ll of the Mac Toolbox code has been written in native PowerPC 601 code yet, so some Toolbox code is actually 680x0 code running in the emulator. Depending on the task, program execution might spend more time in native code--thereby gaining a performance boost--or remain in the emulator for a performance hit.
BYTE's low-level benchmarks support this conclusion. For example, most of QuickDraw has been rewritten as PowerPC code. In the low-level video benchmarks on a Power Mac 8100/80, when a circle fill is done by an algorithm, performance is about that of a Mac IIfx (a 40-MHz 68030). But when QuickDraw is used to fill a circle, performance is as good as on a Quadra 840AV (a 40-MHz 68040). For the screen-intensive word processing application tests, which make heavy use of QuickDraw, the low-end 6100/60 did as well as a Quadra 950 (a 33-MHz 68040), while the high-end 8100/80 bested a Quadra 840AV by a large margin.
The other gotcha is in floating-point performance. Although the 601 is noted for its
high-speed floating-point calculations, much existing application software doesn't tap into this capability. Applications that call SANE (Standard Apple Numeric Environment) for floating-point math will see modest performance, since Apple has ported portions of SANE to 601 code. But applications that use only 68881/68882 FPU instructions won't operate at all, because the emulator doesn't support them. These applications either crash or resort to handling the computations in 680x0 code, which bogs down in the emulator.
This situation is also reflected in the benchmark results. In the BYTE low-level floating-point benchmarks on a Power Mac 8100/80, floating-point performance is equal to that of a 25-MHz 68040 when SANE calls are used. You can expect even better performance when 601 FPU instructions are used directly in future applications. However, in the application tests, both Mathcad (which is used for the Scientific/Engineering tests) and Excel rely on the 68881 FPU for fast computations. With no co
processor, the computations are trapped in the emulator, and performance plummets, skewing downward the overall application index for the Power Macs. Therefore, some particular application indexes are misleading. Judging from my experience, the Power Macs run much faster than these tests indicate.
If you're interested in running a specific category of application on a Power Mac, check the individual benchmark indexes. Remember that the results are only for 680x0 binaries and represent worst-case numbers. Native applications will run much faster: For example, a beta native version of Photoshop was two to four times faster than Photoshop 2.5 running on the same Power Mac.
Like Wine, Over Time
The Photoshop results emphasize an important point: To realize the Power Mac's full potential, native applications are essential. Granted, the emulator is robust and delivers reasonable performance, but it's native application performance that makes the Power Mac shine. A handful of applications were nativ
e when the Power Macs shipped in March, with more on the way. (See the table "Native PowerPC Mac Applications" for a partial list.)
Adobe takes an ingenious upgrade approach, thanks to the extensibility of Photoshop 2.5. The company provides a free Photoshop plug-in module that replaces most of Photoshop's innards with PowerPC code. Microsoft's Excel and Word programs should be native by the time you read this.
Developing native applications for the new processor isn't as difficult as it appears. Vendors who have already written their program in C or C++ for cross-platform porting will only have to recompile their programs with a PowerPC compiler. The Power Mac's new core system software also promotes rapid application development (see "The Power Mac's Run-Time Architecture," April BYTE). Also, a slew of PowerPC development tools are appearing on the market, such as Apple's own PowerPC C/C++ SDK (Software Development Kit), Symantec's Think C/C++ 7.0 compilers, Metrowerks' CodeWarrior C/C++ compi
ler, and Jasik Design's The Debugger (a native debugging utility).
The Mac Toolbox code will evolve over time. Currently, Apple has implemented about 15 percent of the Toolbox as native code. This fraction will increase with future releases of the Mac OS, making current Power Macs run even faster. In an era in which faster desktop computers typically supersede older models in six months, the Power Macs will actually counter this trend, growing faster with new software. It's probably one of the best reasons yet to consider owning a Power Mac.
The Facts
Power Mac 6100/60 (with 8 MB of RAM, 205-MB
hard drive, AV Technologies board, and CD-ROM $2599
Power Mac 7100/66 (with 8 MB of RAM, 500-MB
hard drive, AV Technologies board, and CD-ROM $3989
Power Mac 8100/80 (with 16 MB of RAM, 500-MB
hard drive, and CD-ROM $5659
Power Mac logic-board upgrades for Centris
610/Quadra 610, Centris 650/Quadra 650, and Quadra
800/840
AV systems:
Power Mac 6100/60: $999
Power Mac 7100/66: $1399
Power Mac 8100/80: $1899
Apple Computer, Inc.
1 Infinite Loop
Cupertino, CA 95014
(800) 776-2333
(408) 996-1010
fax: (408) 974-6412
Native PowerPC Mac Applications
Aldus Freehand 4.0 Frame Technologies FrameMaker 4.0.3
Aldus PageMaker 5.0 Ray Dream Designer 3.0
Claris Impact 1.0 Videofusion QuikFlix 1.1
Claris Works 2.1 VideoFusion 1.6
Dayna Communications ProFiles 1.0 WordPerfect 3.0.1
Fractal Design Painter 2.0
Illustration: Power Mac Emulation Performance
Power Mac performance when running 680x0 application binaries ranged from that of a 25-MHz 68030 to better than that of a 40-MHz 68040. Relative speed varies depending on how much the applications use those Toolbox calls that have been rewritten with PowerPC instructions. My tests (not
shown) with a beta version of Photoshop indicate performance several times that of older 680x0-based Macs when running native PowerPc programs.
Photograph: Although housed in Centris/Quadra-type cases, the new Power Macs provide RISC performance at affordable prices. From left to right: the 6100/60 with 60-MHz PowerPC 601 CPU, the 7100/66 with 66-MHz CPU, and the 8100/80 with 80-MHz CPU. Prices start at $1819 for the Power Mac 6100/60, with 8 MB of RAM and a 160-MB hard drive but without a monitor or keyboard.
Tom Thompson is a BYTE senior technical editor at large with a B.S.E.E. from Memphis State University. He is an Associate Apple Developer. Contact him on AppleLink as T.THOMPSON, or on the Internet or BIX
at
tom_thompson@bix.com
.
Power to the New Macs
