After reading Henry Norr’s review of the new PowerMac G5s, you might have wondered why the new dual-1.8GHz model lagged behind its very similar predecessor in a couple of the tests. I certainly did—especially since, aside from the amount of installed memory and the size of the hard drive, the specs for the dual-1.8GHz G5 unveiled in June 2004 and the one introduced in November 2003 are nearly identical. And since we leveled the RAM playing field by installing equal amounts of memory, you’d expect our Speedmark results to be identical as well.
For the most part, the systems performed as expected—you'll notice in the benchmark accompanying Henry’s review how the dual-2.5GHz Power Mac G5 bested all models—but there were a couple instances where the older dual-1.8GHz Power Mac out-performed the newer model. These unexpected results are most likely due to the differences in hard drives.
The older dual-1.8GHz model came with a roomy 160GB Seagate Barracuda hard drive; the newer model features an 80GB version of the same drive. The drive swap seems to have sacrificed not only storage capacity but a little speed as well; note the older model’s faster times in several of our tests. In fact, the older dual-1.8GHz Power Mac even bested the dual-2.0GHz model (featuring a Maxtor DiamondMax 160GB drive) in disk-intensive actions, such as file duplicates and video encoding, although just by a hair.
The performance gap was relatively small and probably not enough to notice in the daily use of your Power Mac. And according to one reader, your experience may be quite different from what we saw in our lab tests. His shiny new dual-2.0GHz Power Mac G5 shipped with a Seagate drive, not a Maxtor.