Hitachi TravelStar C4K60: 1.8", 30 GB
The TravelStar C4K60 carries the same name as Hitachi's 2.5" notebook drives, but is an entirely different product. The rotation speed is only 4,200 RPM, and while the 2 MB L2 cache can be considered a standard size, 8 MB would be attractive from a performance point of view.
Hitachi uses the UltraATA/100 interface and ships CE versions with ZIF connectors, or PC versions that use the Mini-ATA connector. The connector's placement along the length of the drive is intentional, because the length of a 1.8" drive equals the width of 2.5" models: 70 mm or 2.76". This means that any 2.5" drive can be replaced by the C4K60.
The benchmark results of the Hitachi drive are very close to the numbers that Toshiba's 60 GB pre-PMR drive produced: a 20.5 ms average access time and a maximum throughput of 20 MB/s are anything but fast. But then, the C4K60 has several benefits, such as requiring less spin-up power than the Toshiba drives, which helps to increase battery runtime in scenarios where there are frequent drive start/stop cycles. And Hitachi has the upper hand when analyzing drive weight: Toshiba's drives weigh five grams more (0.18 ounces), which corresponds to a 9% or 11% difference for the dual and single platter configurations, respectively.