How It Works: The Sturdiest Solid-State Storage

Next-generation laptops won’t have hard drives. Instead, they’ll use flash memory—the same found in camera memory cards and iPhones. Flash-based drives are thinner, faster and nearly indestructible

By Lauren Aaronson Posted 03.13.2008 at 3:53 pm 6 Comments

Save Small These scanning electron microscope images zoom 10,000x on a flash drive. Made by Micron Technology, the 64-gigabyte, three-by-two-inch drive is destined for notebook computers. Courtesy Micron

Like a traditional hard drive, a flash-based drive stores information in the computer-readable language of 0s and 1s. But instead of writing data by flipping magnetic poles on a spinning disk, flash memory just shuttles electrons around on a stamp-size microchip.

With no moving parts (except, of course, the electrons), a flash drive eats less power and is more durable than an ordinary hard drive. It can even survive a 10-foot drop. (A hard drive can wipe out your data if its mechanical arm scratches its disk.)

The cost per gigabyte is still high, but it’s falling fast, and flash drives are already starting to appear in some laptops.

How Flash Memory Saves a File: Courtesy Micron

How Flash Memory Saves a File

Flash memory stores 0s and 1s in millions of miniature transistors, each 1,000 times as thin as a human hair. If the transistor conducts current, the chip reads it as 1; if not, it’s 0. The current flows just underneath the transistor along the chip’s base, or substrate [A].

When the chip is empty, all transistors are set to 1. But when you hit “save,” the chip records data by blocking the current to some transistors, turning them into a 0. To do so, the chip briefly applies 20 volts to a piece of silicon called a control gate [B]. This pulls electrons onto another silicon bit called a floating gate [C], leaving a positively charged area directly below—and breaking up the usual path of electrical current.

The only way to move the electrons and change the pattern of 1s and 0s—thereby changing your data—is by applying precise voltages to the transistors. That means even kicking your laptop won’t erase your file.

Size: 3 x 2 in.
Capacity: up to 64 GB
Speed: Can save 35 MB per second
Info: micron.com

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6 Comments

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dezscipop

03/23/08 at 9:29 am

I am at last pleased to see that some good stuff is getting out there as this is the way the hard drive should have gone much earlier in its' developement but I think that the powers that be have controlled the "sale of fossil fuels'" which is what the hard discs are made from and that is why we now suffer costly disposal of non-bio-degradable plastic in the hard drive and other componentry in our Pc's and other electronic equipment,we all know who is guilty,don't we,yes,It it the large OIL Companies(all of them) and fundamentally corrupt governments and countries.

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greasytony

03/29/08 at 9:08 am

When flash usb thumb drives and mp3 players which were like 64mb > 512mb started to come out, we were told that the flash memory had a lifespan and has a finite number of writes, if this is the case, what should we use to back up data?

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atown303

04/02/08 at 8:34 pm

This is a really cool and useful article. Not boring and to the point.

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roycebarber

04/04/08 at 3:34 pm

dezscipop is right that greedy groups have screwed us over and now we are all paying for it.

greasytony brings up a good point, are flash drives useful for rapid file exchanges and for use in backing up vital files? if they are limited in number of writes, then why are they being used as hard drives in a six thousand doller appleAir laptop? does apple think we will happily replace the drive when it fails and errases our data?

personally i love solid state hard drives and hope to see more!

Signature: Royce Barber of www.roycebarber.com
Often reading: The Message, The Bible in Contemporary Language.

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eray

04/14/08 at 9:31 pm

:I like dezscipop comment. I have two flash drives in a hub. One (f) small for handeling workable graphic items. One (g) large for tempory B/U storage. The (f) just died shortly after one year of continous useage. The (g) flashdrive is still running strong now for over three years. Their much more versital in every way over a harddrive except for load capacity, cheaper and a lot more usefull.
Eray

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PistolDave

08/25/09 at 12:20 pm

dezscipop,

I can make you a really good deal on some tinfoil hats to protect you when the oil company people in the black helicopters come looking for you.

//sarcasm off

There is actually a quite small amount of thermoplastic in a typical hard drive. The platter is aluminum or ceramic with a cobalt alloy coating, and the cases on most drives are aluminum or magnesium.

The reason that hard drives have been the dominant mass storage technology in recent history is reliability and cost per byte of storage. Only in the last few years has chip manufacturing technology advanced to the point where large capacity memory storage chips can be mass produced for a reasonable price. It is simply the pace of technology development, not some big conspiracy.

Roycebarber,

If not for these "greedy groups" of people funding R&D through profit, we would still be living in mud huts and hunting for food with sticks.