Western Digital has made its line-up of hard disk nice and easy to understand. Caviar Black are the fast, high-end disks for those that want high performance. Caviar Blue are the mid-range disks, and Caviar Green disks are optimised for low energy consumption and silence. WD recently added another colour, the Red series. These are made especially for NAS devices and Home Servers. WD claims they're optimised to run 24/7, but they're more affordable than professional enterprise disks.
To accomplish this Western Digital uses what it calls NASware technology. It entails a number of this, but basically comes down to that the firmware is optimised to work with RAID arrays. A hardware-based feature is that Red disks are designed in such a way that when several of them are present in the same chassis, they won't resonate or interfere with each other. The disks are supposed to stay cooler compared to standard desktop hard drives, and the built-in temperature sensor is accurate to one degree. WD also performs more compatibility tests with NAS devices. The MTBF (Mean Time Before Failure) is supposed to be 35 percent higher than with standard hard drives.
We tested the Western Digital Red 1TB, 2TB and 3TB. They each have 1 TB platters. WD doesn't provide an exact RPM for them, and instead says that the IntelliPower system provides a variable and optimised speed. You can assume that the Red disks will be around 5400 RPM. The disks have a SATA 600 interface and 64 MB cache. The warranty is three years.
The average price of the three disks is £68, £93 and £128, respectively, which is slightly more expensive than the standard WD Green disks.
The main selling point of these Red disks is their long-term reliability, but this is something we can't test, or we'd have to publish the results three years from now when the Red disks are no longer available. So we'll have to take their word for it.