6 SSD Questions, Answered

November 29, 2011

Solid-State Drives Can Boost Performance, Improve Reliability and More, but at a Cost

1. What is an SSD?

Forget file cabinets, photo albums and record collections -- increasingly, our personal computers are where we store life's important documents and memories. For years, the classic PC hard drive was the data-storage device of choice -- but now SSDs are rising fast in popularity.

SSDs use the same type of memory -- NAND flash -- found in USB "jump drives" and SD camera cards. But they're faster and have much higher capacities -- from 40 gigabytes up to 600 gigabytes.

2. Why are they so popular?

SSDs' biggest advantage is that they don't have any moving parts. Regular hard drives store data on magnetized platters spun by an electric motor at thousands of revolutions per minute. SSDs access and store memory in ways more similar to a microprocessor than a hard drive. And because they have no moving parts to break down or to misalign, SSDs are up to 10x as reliable as hard drives.

They're rugged: The lack of moving parts makes SSDs much more rugged than regular hard drives. You can drop an SSD onto a concrete floor, watch it bounce and then plug it back into your computer with no problem. Don't even think of trying that with a regular hard-disk drive.

They're fast: Because SSDs don't have to search for data over the entire surface of a spinning disk, they can access data much faster than hard drives. In fact, SSDs can access and transfer data twice as fast as even the fastest hard drives.

3. How do they improve your computing experience?

In many ways. Here are a few examples:

Faster boot-up times: In one test two identical computers, one with an SSD and the other with a modern hard drive, are turned on at the same time. The SSD-equipped computer has Windows opened and running in 21 seconds. The hard drive-equipped computer takes 101 seconds to boot up -- five times longer!
Faster responsiveness to apps: Opening up a number of programs at once? SSDs can access and open programs up to 66 percent faster than conventional hard drives.
No noise: As hard drives get older, their moving parts tend to wear and they can get noisy. That's not a problem with SSDs -- because they have no moving parts, they make absolutely no sound to distract the computer user from his or her task or entertainment.
Better battery life: SSDs are at least 20 percent more energy efficient than typical hard drives, thanks again to their lack of moving parts and efficient circuit design, meaning users' computer batteries should last longer between charges.
Lower laptop temperatures: Notebooks with SSDs run about 12 degrees cooler than hard drive-equipped laptops. Because they can access data more quickly, SSDs help the CPU and chipset do their job faster and go back to a "sleep" state, keeping the computer cooler.

4. What makes them so fast?

A modern, 7,200-rpm hard drive can access data at a rate of about 150 MB/second. SSDs that use advanced multi-level cell technology, which crams more bits of information onto each transistor, can retrieve data at 500MB/second.

5. Why are SSDs so expensive?

In a nutshell, they cost more to make. SSDs are basically chips made with cutting-edge semiconductor process technology. Right now they're being made with the 25nm process by Intel and will soon transition to an even smaller, 20nm process.

6. When will the price come down?

All that performance does not come cheap. 120GB SSDs are available online starting around $150. For about the same amount, you can get a 3-terabyte hard drive -- 25 times more storage for less money.

While SSD prices are falling by about 50 percent per year, it will be quite some time -- if ever -- before SSDs are as cheap as hard drives, which store data on inexpensive magnetized platters.

But SSDs' sales growth shows that many computer users find the increased performance, energy savings and reliability worth the price premium.