How fast are dual processor Power Mac G5 models compared to single processor models?
According to Apple-published benchmarks of the original Power Macintosh G5 models, the dual-processor Power Macintosh G5/1.8 DP (PCI-X) and G5/2.0 DP (PCI-X) models are roughly 30% and 45% faster, respectively, than the entry-level single processor Power Macintosh G5/1.6 (PCI). MacWorld also published a review with real-world performance tests that you may wish to read as well. The other single processor model — the Power Macintosh G5 1.8 (PCI), introduced as a low-cost model with a 600 MHz system bus (one third of processor speed), not surprisingly, is substantially slower than the “June 2004” dual processor models available at the time of its introduction — the Power Macintosh G5/1.8 DP (PCI), G5/2.0 DP (PCI-X 2), and G5/2.5 DP (PCI-X), which have faster processors, faster system buses (one half of processor speed), and faster architectures. MacWorld reviewed this single processor model as well and concluded that it is not the system for “anyone who does computation-intensive work”
