Western Digital Caviar Black and RE4 2TB Drives Review

More Than Just Spinning Platters

Both of the Western Digital drives are brimming with interesting technologies. Besides their enormous capacities, each drive boasts dual processors; huge, 64MB caches; dual stage actuators; and more.

You've heard of multiple processors. Multi-CPU systems have been around for decades, culminating in the multi-core-single-die CPUs in today's mainstream computers; multiple-GPU graphics cards were common in the days of 3dfx (hell, that was before graphics card processors were even described by the moniker "GPU"). These drives, the WD RE4 and Caviar Black hard drives feature a pair of processors onboard.

What benefits do multi-CPU drive controllers offer? Quite simply, doubling the processing power of a hard drive should increase its performance noticeably--and platter drive manufacturers are looking for any way to compete with SDD drives in performance (obviously, the former already has the latter trumped in terms of capacity). The dual CPU architecture should just about max out the efficiency of the big buffer.

Meanwhile, what's up with a pair of actuators? WD employs a traditional actuator to zap the drive heads to the right general area of the sought-after data, and then kicks the show off to a piezoelectric actuator to quickly zoom in on the exact location. The one-two punch is supposed to reduce "short" seek times to right around 0.4 milliseconds.

That's a heck of a task with four platters each weighing in at 500GB. To extend the life of such dense drives, WD employs NoTouch Ramp Load technology. That means that, unlike CSS (contact start stop) based drives, WD drives make sure the heads and the discs never touch each other.

That all adds up to terrific theoretical performance with a low chance of data loss. We obviously can't test the longevity of hard drives (unless you give us ten or so years to report back), but performance is something we can easily quantify.