Not All 500 GB Hard Drives Are Created Equal

When hard disk manufacturers transition from one product generation to the next, they typically introduce the new drives with higher capacities, better performance, lower power consumption, and improved feature sets. However, it becomes more difficult over time for manufacturers to improve their products, as most of the progress happens inside the drive. It turns out that only users who know about the details are able to tell apart outdated products from the latest ones that normally should be preferred.

We looked at two 500 GB notebook hard drives by Samsung to illustrate the difference between first-generation drives and the latest products. We found that they appear very similar, but perform quite differently.

Data Density Counts

Hard drive makers live or die based on their ability to increase data density; the largest hard drive volumes are sold in the so-called “sweet spot,” which is dominated by drives that are based on a single rotating platter. These are currently 200 and 250 GB 2.5” notebook hard drives and 320-500 GB 3.5” desktop drives. Each of those capacities are the cheapest to manufacturer, and the drive maker who reaches new capacity points first typically has an edge over the competition until others catch up.

High spindle speeds can be considered the trade-off against high capacities, as vibration, heat dissipation, reliability, durability, and power consumption (among other factors) become an issue with faster rotation. Hence, the fastest drives come with much smaller platter diameters to meet all of these demands, and hard drive makers will try to avoid the highest rotation speeds in the mainstream for these reasons, as capacity is easier to sell.

Going from Three to Two Platters

We selected two Samsung drives, because we had to send Samsung’s first-generation 500 GB 2.5” notebook drive into our last notebook hard drive roundup, where it wasn’t capable of competing with the latest products from the other drive makers in many benchmarks. The reason for this was its internal structure: Samsung was quick to market with its 500 GB 2.5” drive, but it was based on three platters, while the newer competition runs on only two platters.

This article compares the three-platter Spinpoint M6 HM500JI with the new Spinpoint M7 HM500LI, which was designed to store the same 500 GB capacity on two platters. Needless to say, this comparison serves a general purpose, as other generational evolutions (such as Hitachi’s Travelstar 5K500 being replaced by the 5K500.B) result in comparable findings. Yet it's worth noting that Samsung was the first hard drive maker to squeeze three platters into the 9.5 mm standard drive height. All other first-generation 500 GB drives (there was Fujitsu’s MHZ2 BT as well) were built at a 12.5 mm height that doesn’t fit into all notebook designs.