[accesscomp] Dan's Tech Tip
- From: "Bob Acosta" <boacosta@xxxxxxxxxxx>
- To: "Bob Acosta" <boacosta@xxxxxxxxxxx>
- Date: Tue, 14 Feb 2012 20:57:20 -0800
Dan's Tech Tips:
Should You Defrag Solid-State Drives?
Article Source: Kim Komando's tip of the day 3/18/2011
No, defragmenting solid-state drives isn't necessary. In fact, it's not a good
idea at all. Read on to find out why.
Let's refresh our memories about how hard drives work. That will help you
understand why SSDs follow different rules. We'll start by talking about the
traditional hard drive.
A traditional hard drive uses magnetism to store information. Inside each drive
is one or more "platters." These platters are metal disks that spin rapidly.
The standard speed for desktop hard drive platters is 7,200 RPM.
Each platter contains billions of microscopic magnetic regions. These regions
can be either magnetized or de-magnetized. The computer reads those as binary
ones and zeros, respectively. Strings of ones and zeros are how all computer
information is stored.
A magnetic head reads and writes information on each platter. The head is
mounted on a swinging arm. It has to physically move across the platter to find
information.
It's actually the same idea as a turntable record player. The magnetic head is
like the record needle. The difference is that the hard drive head hovers over
the platter. When the head touches the platter, you have a serious problem.
This approach has worked for decades, but it has some drawbacks. One major
problem is reliability. There are a lot of moving components that can fail.
And when they fail, your information is often severely damaged. That is why
having a backup system is essential.
Another problem is speed; the components can only move so fast. This limits how
quickly information can be written and read. Some drives spin the platters at
10,000 RPM or higher. That increases data transfer, but it also wears the drive
out faster.
The moving parts are also a problem as hard drive storage gets bigger. There is
more information on the drive to search. Finding the right file can take longer.
That leads us to the most common problem, which is fragmentation. Fragmentation
occurs on every computer during normal use. Files are constantly being moved,
written, changed, deleted and overwritten.
You often end up with one program file in one spot. And a related program file
will be in a completely different spot. You might even have one file broken up
into several locations.
What happens when the computer accesses that program or file? It has to visit
several spots on the platter to assemble it for you. And that takes extra time.
Your computer slows down.
You can visualize it this way. Imagine listening to a vinyl record where every
song is broken into segments. And those segments are scattered around the
record.
Listening to a song would be annoying. The needle would have to lift and move
to each new segment. That means the song would keep pausing. And listening to a
complete song would take forever.
That is why defragmentation programs exist. These move related information back
together on the platter. This means the head doesn't have to move so much. It
helps your computer run smoother.
Now let's talk about how solid-state drives work. These have been around for
years. But until recently, they were way too expensive for most consumers.
They are still more expensive than traditional hard drives. But prices are
falling rapidly, and SSD storage size is increasing. In fact, SSDs are the only
option on some laptops now. The MacBook Air is a good example.
SSDs are built around flash memory. That's the same technology used for thumb
drives and memory cards. Most media players, tablets and smart phones use flash
memory as well.
Flash memory is made up of cells. There are a few different kinds of these
cells. But we don't need to worry about that for the moment.
The upside is that there are no moving parts, hence the "solid state" moniker.
Everything is read and written electronically. That increases both reliability
and speed.
It also makes fragmentation a moot point. It doesn't matter where files are
located on the SSD. There are no moving parts to slow things down. Reading
files from multiple locations takes no extra time.
In fact, defragmenting an SSD is actually not good for it. That's because flash
memory has a major drawback: It wears out over time.
Flash memory is made up of billions of cells. Writing information changes the
contents of the cell. Unfortunately, each cell can only be changed so many
times. After that, it won't change anymore. Eventually, your SSD loses all its
storage space.
Flash cell lifecycle is being steadily improved. A modern, SSD from a reputable
manufacturer should last at least 5 years. Much of that is thanks to
wear-leveling controllers.
These controllers monitor how often each cell is used. They make sure data is
spread evenly throughout the drive. This keeps cells from being worn out too
quickly.
Manufacturers are also over-provisioning. This is putting more memory in the
drive than is listed. If some cells fail prematurely, they can be ignored with
minimal impact.
Defragmenting a drive moves a lot of data around. This means you are changing a
lot of cells at once. And that means you are wearing the SSD out more quickly.
Of course, the impact is slight overall. It would take a lot of defragmenting
to wear out the drive. But, again, it doesn't actually help performance.
If you want to get an SSD, make sure you have Windows 7. It is designed to work
properly with SSDs. Earlier Windows versions will treat the SSD like a regular
hard drive. This means you won't get many of the benefits.
Also, remember that SSDs are still largely new to the consumer market. You will
probably encounter poor products and manufacturing errors. Having your
sensitive information backed up is still very important.
Below are some sites to review and compare solid state drive
cost/size/performance:
1. Solid State Hard Drive - Hard Drives - Compare Prices, Reviews and Buy at
Nextag - Price - Review:
http://www.nextag.com/solid-state-hard-drive/products-html
2. Solid State Drive Comparison Round 2, Techspot Review:
http://www.techspot.com/review/181-solid-state-drive-roundup2/
3. Solid State Review, Top Ten Reviews for 2012:
http://solid-state-drive-review.toptenreviews.com/
4. Review: Hard disk vs. solid-state drive -- is an SSD worth the money ...
http://www.computerworld.com/s/article/9134468/Review_Hard_disk_vs._solid_state_drive_is_an_SSD_worth_the_money_
5. SSD Vs HDD Performance Speed Life Cost Power Reliability
http://www.teknocrat.com/ssd-vs-hdd-analysis-and-comparison.html
If you have any questions about the tips posted in Dan's Tech tips, please
contact Dan at the following email address:
dthompson5@xxxxxxxxx
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