Power Consumption Comparison
The following table lists the idle (minimum) and high activity (maximum) power requirements for all three popular hard drive form factors. The results are a summary of what we've seen in our test labs and don't refer to a particular product. Note that there can be considerable power differences between two drives of a particular drive family, because higher platter count increases idle and maximum power requirements. The interface has quite an impact as well: expect SATA or SAS drives to consume more energy than UltraATA or UltraSCSI hard drives.
|Power Requirements||Idle Power||Max. Power|
|1.8"||0.3 - 0.5 W||~ 3 W|
|2.5"||0.3 - 2.0 W||~ 5 W|
|3.5"||4-10 W||~ 20 W|
1.8" hard drives can be found in various subnotebooks such as the Dell Latitude D420, some PDAs, UMPCs (ultra-mobile PCs), portable MP3 and media players, mobile storage devices (external 1.8" hard drives), certain car electronics products, and digital camcorders such as the Everio series by JVC or Sony's DCR-SR100.
You should not purchase a computer product, which is based on a 1.8" hard drive, if you put high emphasis on performance. Subnotebooks, such as the Dell Latitude D420 mentioned above, are extremely small and light, and they certainly offer sufficient performance for office and multimedia jobs, but the subjective performance suffers from the slow 1.8" hard drive. Expect Windows and applications to take considerably more time to start - that's the price you pay for ultimate mobility. So far, all 1.8" hard drives utilize an UltraATA/100 interface, because it requires less energy than Serial ATA.
Despite this limitation, the 1.8" form factor is more attractive for notebooks than it may look, because the future will bring more and more flash-based hard drives. First generation solid-state/flash hard drives are mostly based on a 2.5" form factor: Sandisk, Supertalent, Transcend and other memory makers are ready with 16 and 32 GB Flash drives using the SATA interface. Most of them should offer twice the data transfer rates of 1.8" hard disk drives, but of course, the capacities cannot compete with them (yet).
ZIF Connectors: Too Sensitive!
All Three Toshiba 1.8" drives we received at our test lab were equipped with a ZIF/LIF interface, which stands for zero insertion force / low insertion force. The alternative is the Mini IDI interface, which uses the CompactFlash pinout. Consumer electronics devices typically use the ZIF connector, while computer products are based on the CF type. The latter is much more robust if you intend to exchange the hard drive once in a while. Be careful when handling ZIF: the connector durability is specified for only 20 (!) insertion cycles. At the same time, most 1.8" drives are specified to run in environments of up to 60°C, which is more than many desktop hard drives can endure.