Choose Or Lose: Which HDD Is Right For You?
At the moment, four companies supply 3.5" drives, which are what we call desktop drives: Hitachi Global Storage Technologies (www.hgst.com), Samsung Electronics (www.samsung.com), Seagate Technology and Western Digital Corporation. Note that the industry has seen some consolidation; in 2003, Hitachi took over IBM's HDD division, and Seagate bought Maxtor last year.
If the only thing you need is more capacity to store your digital data, the online retailer with the lowest price will suit your demands. The price per gigabyte of capacity is most crucial for you. At the moment, drives from 200 to 320 GB are the best choice in this category. Our Interactive Hard Drive Charts offer valuable assistance, since this service calculates the costs per gigabyte for numerous models on a daily updated price basis.
Of course there still are differences between various hard drive families, differences that may vary under changing application requirements. The most important factor is a hard drive's rotation speed - its spindle speed. 7,200 RPM drives are common for 3.5" desktop HDDs, while slower models have almost vanished. Speeds of 5,400 RPM are still pretty common in 2.5" HDDs for laptops, because increasing rotation speed demands more energy, which definitely is an issue for mobile computers.
Western Digital's 10,000 RPM Raptor provides an interesting option for faster computer systems. In the beginning, these drives were intended for small servers and workstations, but they have also become more popular for high-end desktop PCs. Simply put, the Raptor remains your first choice if you are looking for a fast hard drive. The 74 GB and 150 GB models, however, don't offer a lot of capacity and tend to get pretty warm, so we have to recommend active cooling precautions.
You will also encounter differences with regard to the size of the installed cache memory, the interface, and the intelligence provided by the HDD controller. Most drives come with 8 or 16 MB cache, although a larger cache only increases performance in a measurable, not noticeable way. By "intelligence" we refer to features such as vibration compensation, automatic parking of heads in case of physical shocks, and Native Command Queuing (NCQ). This latter option enables the hard drive to sort pending commands in such a way that they can be executed with the least repositioning of heads. This feature is intended to optimize latencies, such as when a platter still has to perform half a rotation before the required section can be read, or when heads have to be moved to a different track.
SATA/150 Or SATA/300?
Serial ATA interfaces are the best way to connect your hard drive, because SATA offers a bandwidth of 150 or 300 MB/s. But don't be swayed by these figures: a hard drive's maximum data transfer rate when reading from or writing to the magnetic platters is still the most noticeable factor in performance. A fast interface merely makes sure that you won't encounter a bottleneck during the transfer. The best example is yet again Western Digital's Raptor: it's the fastest desktop hard drive, and gets along just fine with SATA/150.