Noise Level Measurements
The very best drive for low noise levels is Seagate's Barracuda ATA IV (40, 60, 80 GB), but the WD drives have no reason to be ashamed, either. Subjectively, the idle and access noises are not intrusive, so the differences in noise level generated among the latest models can be considered quite small.
Our temperature measurement reveals excellent work for Western Digital: 45 degrees Celsius is the lowest value that we have ever measured with a 7,200 rpm drive. Though the drives from IBM and Seagate are not much hotter than that, a low-temperature drive is quite important in order to keep the whole computer as cool as possible - particularly in times of CPUs that heat up with 40 Watts or more.