Washington  - For years, the biggest bottleneck in personal computers has not been processor speed, memory, or video cards. It's been the hard drive. Thanks to the emergence of solid state disks (SSD), that's about to change.

Instead of spinning platters that can never spin quite fast enough to keep up, SSDs store data on memory chips - flash memory, to be precise. Early models have been both prohibitively expensive

and of capacities that were too meagre to be of interest. Things are different now, though, and an SSD just might be the best choice for your storage needs - now. Read on to learn more.

Q: Why should I consider an SSD over a traditional hard drive?

A: SSDs are much faster at reading data than are traditional hard drives. That means your operating system will load faster and applications will load and run faster. Solid state drives also run cooler and quieter - and they consume less power. Because there are no moving parts, they are essentially silent, in fact. Low power usage means longer battery life in notebook computers.

Finally, SSDs are not nearly as fragile as traditional hard drives. If you drop a notebook computer with an SSD in it, the drive will probably survive, although the notebook itself may not. A traditional hard drive is quite sensitive to shock and may easily be damaged if dropped while running.

Q: What are the disadvantages?

A: Primarily low capacity and high cost relative to traditional platter-based drives. Capacities of SSDs currently top out at around 128 gigabytes (GB) - plenty for a notebook hard drive but meagre compared to the 500 GB to 1.5 terabyte (TB) capacities offered by traditional hard drives.

Cost is currently high when compared to platter-based drives, but thanks to competition and the increasing popularity of these drives, prices are coming down quickly. Currently, 64 GB SSDs are retailing for around 150 to 225 dollars, although some models with dramatically higher performance ratings cost several times more.

Q: Are SSDs compatible with my current computer?

A: Yes. Most SSDs today come in the 2.5-inch form factor, which means they're the same size as today's notebook and laptop computer hard drives. And they use today's SATA connectors, so no special cabling is required to hook them up to recent-vintage computers.

Most of today's notebooks will recognise SSDs as a conventional hard drive, with no further driver or software installation necessary. Occasionally you may need to update the "chipset" software for your notebook's motherboard, however, in order for the drive to be usable in your system. Before you swap out your old hard drive for an SSD, it's a good idea to first update any drivers or software available for your system from the manufacturer's Web site.

Most desktop computers are designed to accept larger hard drives in the 3.5-inch form factor. You can still use an SSD in a desktop computer, but you'll probably need a
3.5-inch adapter kit which will allow you to secure the 2.5-inch drive into the drive bay of the desktop computer. These adapter kits are widely available - search for "2.5 to
3.5 inch drive adapter kit" - and are usually inexpensive.

Q: Who makes solid state drives?

A: Storage consumers are used to buying products from disk drive makers such as Seagate, Western Digital, and Hitachi. These names, though, are largely absent from the SSD market. Instead, the memory makers are putting out SSDs. So when you go shopping, you'll find models from vendors such as Intel, Patriot, OCZ, Transcend, Ridata, G. Skill, and others. Thanks to the abundance of players in the market, price competition is in full force and is making these drives affordable.

The traditional magnetic storage manufacturers such as Seagate and Western Digital are late in bringing out products, but most have either announced a move into the market or are readying products.

Q: What is the life expectancy of an SSD?

A: Flash memory - the stuff of which SSDs are made - does not last forever. Its life expectancy is reduced each time data is stored on it. However, SSD manufacturers are using a technology called "wear leveling," which ensures that data written to an SSD is distributed evenly across the memory cells that make up the drive. Thus the overall life expectancy of the drive is maximised.

Current drives are estimated to last anywhere from 2 to 15 years - with the lower number being the life expectancy when data is written to the drive constantly and the higher number representing the life expectancy of a drive under normal use. Conventional drives cannot be expected to last any longer under the same conditions, so life expectancy should not be a factor in whether you purchase an SSD.

Q: Is it necessary to defragment SSDs?

A: No. In fact, defragmenting an SSD will reduce the life expectancy of the drive and do nothing to improve performance. The idea behind defragmenting a conventional hard drive is that by placing files and pieces of files contiguously, the read-write heads will be able to retrieve information faster and therefore improve performance.

But with SSDs, there are no read-write heads - indeed, no moving parts - and all data, no matter where it is placed, is accessible with the exact same speed. So you should not defragment an SSD, and you should turn off any automatic defragmentation routines that you may have set up for your conventional disks.

--- Have a computer question? Send it to the Computer Helper at jayd@csi.com. (dpa)