Apple Power Mac G5
The key improvement to the new line of Power Macs is the PowerPC G5 processor, developed jointly by Apple and IBM. The G5 architecture is much stronger in accessing memory and handling computing-intensive tasks without repeated, time-consuming trips to the hard drive.
The G5 also will bring 64-bit processing to the Mac platform, allowing an exponentially greater ability to handle integers than the previous 32-bit processors. As with the AMD Athlon 64, applications need to be optimized for 64-bit computing to take full advantage of the architecture. But the PowerPC G5 (like the Athlon 64) will continue to run 32-bit applications (like those in our test suite) natively instead of in emulation mode, as with Intel's 64-bit Itanium processor.
As of this writing, only a few programs have been updated for the G5; these include Adobe Photoshop 7.0.1, Emagic Logic 6.2.1, and PyMOL 0.91. Current users can download 64-bit plug-ins or upgraded versions of each. Apple expects many more programs optimized for the G5 to reach consumers by year-end. (To help that effort along, third-party programmers can download a free set of development tools from Apple's site, which analyze programs and offer tips on optimizing for the G5.)
The G5's improvements would be nothing without a radically improved underlying system architecture. Apple has matched the chip with a 1-GHz front-side bus per processor (up from 167 MHz with the G4), for a total FSB bandwidth of 8 GBps (up from 1.3 GBps). You can load a G5 with up to 8GB of 128-bit, 400-MHz DDR SDRAM (2GB of 64-bit SDRAM was the max on the G4), as well as new 160GB Serial ATA hard drives. Hence even nonoptimized 32-bit applications will see a significant performance increase compared with the way they run on a Power Mac G4.