All about Solid State Drives

Solid State Drives (SSD) have been the buzzword for years now.  I’m sure you’ve heard about them but if you’ve never contemplated how they work you’ll be amazed at both how simple and complicated these technical marvels are.

A SSD is a hard drive without a disk.  There are no moving parts inside.

Traditional hard drives (HDD) used spinning magnetic disks and a movable arm, known as an actuator arm, which had a tiny needle affixed to the end called a head.

To read and write data, vertically stacked disks known as platters would whirl around a spindle at a blazing fast 7,200 revolutions per minute.

When you request a file, the head seeks the data position on the disk. Most of the time the head glides above the platter and all is well; however, if you drop your laptop the computer crashes.  Techies call it a crash because the read/write head physically crashes, or knocks into the spinning platter which inevitably results in data loss or a frozen computer.

Thankfully SSDs aren’t susceptible to crashes in this way because they use semiconductor chips to store data.  You might be surprised to know that this technology isn’t new.  In fact, motherboards have been using semiconductors to manipulate memory almost since the inception of the Personal Computer in the 80’s.  That’s what Random Access Memory (RAM) is.

We call RAM volatile memory because it doesn’t persist after the machine loses power.  Conversely, the chips that store information in SSDs are known as non-volatile memory because the information remains even without a power source.  It’s basically a bunch of super tiny transistors arranged in a grid that respond to minuscule voltage changes.

Why you should care about Solid State Drives

SDDs are all the rave because of a few things… okay – really just one thing:

  1. They make your computer fast

Once you swap out your old HDD for a SSD you’ll notice your computer boots faster, applications load quicker, and the system has more get up and go.

How much get up and go?

Let’s talk about read and write speeds.  On average SSDs facilitate data transactions over 3 times faster and access data over 8 times faster than regular hard drives.  The price per Gigabyte still isn’t comensurate with traditional HDDs but I think the performance improvements, nearly silent, lighter, more impact resistant SSDs make up for any cost liabilities.

Some people retort:

But the SSD has a shorter life expectancy than HDDs!

Well, technically that’s true.  While SSD’s support a virtually unlimited number of read operations, there is still a limit to how many times you can write data to the disk.  Traditionally HDDs didn’t have this problem – but I have to ask: is this really a problem?

Today’s SSDs will give you about one million hours of write operations.  Translation: over 114 years. Consequently, I don’t see write endurance as a real liability here.  Drive manufacturers spread out the transistors in such a way that they all wear at the same level.  This is known as wear-leveling and means that most SSDs last for about 5,000 cycles.

USB drives have been subject to this same problem yet no one complains about a wear-leveled USB drive.  Besides — this isn’t a real issue because 5,000 cycles is about 30 years of continuous writing anyway.

In addition, SSDs are cheap.

Once upon a time SSDs used to be the purchase of only big companies and affluent consumers but now the price has significantly dropped which; consequently, has made them available to the masses.  For example, you can buy a 360GB SSD on sites like NewEgg for a little less than a $1 per gig.  In fact, according to the Tech Report, the cost per capacity of SSDs is about 59 cents per GB.

How to decide which Solid State Drive to buy

Don’t worry about speed because all SSDs are speedy.  It’s kind of like walking into an exotic car lot and trying to figure out which supercar to buy.

SATA III

If you must look at speed just make sure it has support for SATA 3.  SATA  3 can transfer data at 6Gbps which is double SATA 2 at 3Gbps.

Error-correcting Code Memory

Also known as ECC memory, this is a special type of memory that can detect and correct corrupt data.  The disadvantage is that it costs a little more and may actually lower performance by about 2 to 3 percent on some computers but in my opinion the advantage of reliable data usurps any alleged disadvantages.  I mean, what good is a fast SSD if all your data is corrupt?

Read Reviews

This last one is common sense but I had to include it for completeness.  Check sites like Amazon and TigerDirect for reviews.  Take into consideration the volume of reviews then focus your selection on two particulars:

  1. SSD manufactures who have been in the business the longest. OCZ and Pure Storage are exemplary companies.
  2. Reviews that are 4.5 or greater on a five point scale.

Getting your data on to your new drive

After you’ve purchased your drive and ripped the box open like a kid on Christmas, you’ll want to transfer all your files.  Howtogeek has written an excellent article about how to transfer your Windows 7 system to a new SSD.  It takes a few steps though so make sure you have enough time.

Here’s what you want to do:

  • Backup your files.  I back mine up to the cloud using Skydrive and Google Drive but keep in mind, if you have a lot of files you might not have enough space to upload everything – plus, it’s going to take a long time to upload everything.
  • Install your Operating System on the SSD
  • Transfer your Libraries or Home folder.  If your name is jdoe on a Windows machine then you’ll want to copy the jdoe folder in Users:
C:\Users\jdoe\

Final things to keep in Mind

  • Never defrag your SSD
  • Use Sleep not Hibernation
  • Don’t max out the capcacity

Never Defrag Your Solid State Drive

Defragmentation is a coherent idea on an traditional electromechanical disk.  Eventually file regions become scattered across the platters so they are no longer contiguous.  So it takes longer for the read/write head to access files because instead of moving to an adjacent region it has to skip around which results in slower performance.  Defragging reorganizes file fragments on the disk into related regions.

But a SSD has no moving parts so defragging is useless because there’s no mechinical arm jumping around a spinning platter seeking data.  But more importantly, defragging a SSD is deleterious to the durability of the drive because it wastes read/write operations.  Fortunately Windows and Mac OSX are pretty good about disabling this automatically but just make sure you don’t unwittingly defrag your SSD in the future.  This isn’t the way to speed up a slow SSD.

Sleep, don’t Hibernate

Solid State Drives recover from Hibernation almost as fast as they recover from sleeping; therefore, there’s no speed reduction in choosing one over the other but there is a penalty for using Hibernation since it forces the drive to allocate extra space to recover your files.  That allocation costs read/writes.  Gratuitious read/writes are bad with SSDs so anything you can do to ration these will maximize the life of your storage drive.

Don’t max out the capacity

As you write data to a SSD it goes on the hunt for an empty block to put the data in.  Think of it like a cubbyhole.  Writing to a free block is what the SSD craves; this is optimal performance.

Windows 7 and Windows 8 support a command known as trim which empties the cubbyhole so it’s ready to receive new data.  trim maximizes drive performance.

As you keep saving stuff to the SSD you have less empty blocks and a bunch of partially filled blocks.  But the SSD can’t use these half-filled cubby holes so it has to perform the laborious task of reading these half-filled cubby holes into memory, modifying it there, and then spitting it back onto the drive for storage.  This happens constantly so the drive slows down.

The key to fixing this problem is to leave 10-15% of your drive free at all times.

So let’s say your drive is 85% free and you have a C: and D: partition.  But the C: partition is 95% full. Since the C: partition has less than 5% free your drive performance is going to suffer.

The Bottom Line

Solid State drives will make your computer faster.  Now that they are affordable you should start investigating your options.  Explore the best reviews, confirm the drive has ECC memory, and SATA III.  There are also free tools to migration your data – just make sure you don’t defrag your drive, fill it up, or hibernate the computer too often.

About

Connect with Vonnie on Twitter

Posted in Hardware Tagged with: