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How Solid-state Drives Work

Actually, Seagate makes something called a hybrid drive, which combines solid-state and hard disk drives in one package. This model packs 750 gigabytes.
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In 1956, IBM shipped the world's first hard disk drive, or HDD, in the RAMAC 305 system. The drive used 50 24-inch (61-centimeter) platters, stored a meager 5 megabytes of data and took up more room than two refrigerators. Oh, and the cost? Just $50,000 ($421,147 in 2012 dollars).

Since then, hard drives have grown smaller, more capacious and, thankfully, less expensive. For example, the Seagate Momentus laptop hard drive, with a form factor of just 2.5 inches (6.4 centimeters), offers 750 gigabytes of storage for less than $100. But even with advanced protection technologies, the Momentus drive, like all HDDs, can crash and burn, taking precious data with it. That's because hard drives have mechanical parts that can fail. Drop a laptop, and the read-write heads can touch the spinning platters. This almost always results in severe data loss.

Luckily, a new kind of computer drive could make crashes as obsolete as your Apple IIe. Known as a solid-state drive, or SSD, it uses semiconductor chips, not magnetic media, to store data. Your computer already comes with chips, of course. The motherboard contains some that house your device's system memory, or RAM, which is where information is stored and processed when your computer is running. Computer types refer to such memory as volatile memory because it evaporates as soon as your machine loses power. The chips used in a solid-state drive deliver non-volatile memory, meaning the data stays put even without power. SSD chips aren't located on the motherboard, either. They have their own home in another part of the computer. In fact, you could remove the hard drive of your laptop and replace it with a solid-state drive, without affecting any other essential components.

But why would you want to? And what exactly would the drive look like -- a green, printed circuit board or a brushed-metal box resembling a traditional hard drive? We'll answer those questions on the following pages, but before we give your machine a makeover, let's review a few computer science basics.

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