Every modern hard drive is perfectly capable of handling your everyday data, and most drives perform well enough to support everything you want to do today. If you are of an impatient nature and have a loose budget, or if your requirements are simply very high, you should always go for a 10,000 RPM Western Digital Raptor drive. Everyone else can buy into a decent 7,200 RPM model at a variety of capacity points for a reasonable cost.
It is undeniable that hard disk storage capacities have by far outrun gains in performance, which is why the hard drive remains the most noticeable bottleneck in modern PCs. As soon as you start your PC or turn it off, launch applications, read or write files or move large amounts of data, you'll experience annoying delays due to hard drive activity. Faster drives and interfaces help to reduce the waiting, but not even a multi-drive high-performance RAID array will get rid of storage-originated delays entirely.
Nevertheless, there is no point in looking for culprits here. In fact, we have to underline the fact that the hard drive manufacturers are doing an incredible job in increasing storage density, while still being able to squeeze some more performance out of hard drive technology that has only changed in the details after 50 years. (IBM's 305 RAMAC was introduced in 1956.)
The performance situation won't change unless technology changes dramatically. As long as hard drives keep using magnetic platters, there is not much that can be done to remove the inherent bottlenecks of physical mechanisms. Fortunately, next-generation hard drives will mostly be based on perpendicular recording technology, which allows building multi-terabyte hard drives while further increasing performance.
Windows Vista will try to improve the user experience on the software side. The new OS will introduce smart pre-fetch and caching features such as SuperFetch, which caches the users' favorite applications into available main memory to make them instantly available. Other technologies such as Flash hard drives can reduce access times to a minimum, but only at a high per-gigabyte cost, and Flash has not yet been possible to outperform a quick hard drive's data transfer rates.
The best compromise may be a combination of Flash and magnetic memory - so-called "hybrids". This technology would allow the operating system or the user to prioritize where important data should be stored, to reduce delays and further improve the overall computing experience.
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