Squeezing 500 GB Onto Two Platters
The hard drive market seems to be spinning faster than the drives themselves, with news arriving on an almost daily basis. Seagate just announced that it will release flash SSD drives this year. Traditional hard drive maker Fujitsu first said that it intended to support UltraSCSI for a few more years in an effort to cover this niche, but then said that it wanted to get rid of its hard drive business, leaving an unclear future for the division. Western Digital is a likely customer, and it is also WD that has managed to introduce the first fully-standard 500 GB 2.5” mobile hard drive.
There Are Small Differences At 500 GB
But is a 500 GB notebook drive really anything new? Looking at it from a capacity standpoint alone, it is not. Hitachi has had the Travelstar 5K500 and Samsung has offered its Spinpoint M6 (HM500LI) drive for a while, and both are 2.5” models. Hitachi deserves kudos for being first to market at this capacity point. Samsung was the first to squeeze it into a 9.5 mm height format. However, both reach their high capacity based on a three-platter design.
While the Hitachi drive is based on a 12.5-mm z-height, Samsung actually managed to fit three platters into the standard 9.5 mm height, which was a first. Both sizes are common for 2.5” mobile hard drives, but the smaller one is necessary for over 90% of all notebook designs. The 12.5 mm drives can be used for other low-power or small form factor storage appliances, set top boxes, media players and such, but are simply not standard for notebooks.
Less Is More
There are several reasons why making the move from three platters to only two platters is appealing. First, the capacity per platter, and hence the storage density, increases, which may result in improved throughput. We will reveal more details in this review, but the throughput experiment was a successful one. Second, the reduced platter count results in fewer moving parts, which has a positive impact on drive power consumption. Last but not least, WD is able to move the hard drive sweet spot from 160 GB to 250 GB, as drives utilizing only a single platter typically are the cheapest models, which system integrators often prefer. Being able to offer more capacity in common configurations may provide a business advantage for Western Digital (though Seagate’s new Momentus 5400.6 will follow in a few weeks).
Let’s see just how good WD’s new storage top model for notebooks really is.