It might be the case that RPM is actually fixed at 5,400 as making it variable would be too complex to design with almost no benefit to power consumption. But again, WD is not disclosing exact rotational speeds, perhaps fearing that this fact would curb sales.
Western Digital has finally announced their much rumored and record breaking 2TB internal hard drive today. Dubbed the 2TB Caviar Green, this 3.5-inch unit includes 32MB of cache and is based on a 500GB per platter design that effectively provides a storage density of 400 gigabit per square inch – the highest offered in any production drive at this time. The “environmentally friendly” drive also includes a few power-saving tricks, such as the ability to modulate between a 7,200 RPM and 5,400 RPM rotational speed (See update).
In addition to the 2TB model, Western Digital is also launching a 1.5TB model along with a revised 1TB model. Exact prices aren't mentioned for any of the drives but the 2TB version is already showing up in Australian online stores for around $299. Additionally, HotHardware had a sneak peek at the drive and has some benchmark results to share – in a nutshell the 2TB Caviar Green managed to hold its own against the Spinpoint F1 and Barracuda 7200.11. Seagate may very well have its own 2TB model lined up for release (after all they have had a 1.5TB drive in the market for some time) but perhaps they’ll want to wait a bit longer and be extra cautious after their recent firmware woes.