An Introduction to the Solid State Drive

[Les]

Introduction

I thought I would put this thread together to help the NBR community as SSDs are coming upon us so quickly and the interest seems to be going through the roof. Since my first article 'Comparing SSD Performance to Mechanical SSD Performance in a Dell Laptop' and consequently, my follow up to that 'Showdown at Big Sky -- Sandisk 32GB SSD Vs. Seagate 160GB 7200RPM HD', the interest in the SSD has become overwhelming with respect to PMs received, questions and advise given.

What Is a Solid State Drive and how is it Different from a Hard Drive?

To start, lets tackle the question of exactly what is an SSD and what are the benefits. The easiest way to describe this is as an SSD being an array of flash memory modules similar to a flash drive which are controlled in such a way that, once the computer is shut off, it retains its memory unlike normal RAM. The SSD is totally different than RAM, in that it is made of flash memory rather than volative memory, thus bringing into existance the term 'solid state memory'.

There are no moving parts within a solid state drive which is the critical difference between that and the hard drive which must rely on mechanical operation to store and retrieve data. In order to access or store data, the HD relies on a metal disk to spin at a speed of up to 7200 revolutions per minute and an arm that extracts or places the information on the disk.

To assist, I'm going to use some pictures, the first borrowed from Mtron to assist in explaining the differences.



What are Its Advantages?

The advantages of a SSD are numerous. First and foremost the sheer speed of the SSD is the most obvious and overpowering feature. It's reasoning is simple. There is no requirement for the disk to spin and the arm to find the exact position of the information it is retrieving. Lets think of the SSD as a book. One simply has to look at the index and then retrieve the information knowing the proper chapter and page. This alone will allow much quicker boot and access times as shown in this YouTube Video taken at CES2007.

My startup time is steady around 27 seconds, this being on a Dell M1330 with a 2Ghz C2D processor, 4Gb RAM, Sandisk 32Gb SSD and running Vista Ultimate 64 bit. I determine my test results from the push of the button until the internet connection is confirmed and all activity has stopped on my desktop. It is a very healthy jump over my former times of well over a minute as this includes an array of software to start during startup as well.

Initial performance results of the SSD were very good, however, tests conducted by websites such as Tomshardware.com showed the SSD to be lacking in write speeds, some being as low as 14mb/s. Technological advance is already showing companies like Mtron, whos original SSD blew away the competition at 100 MB/s read and 80 MB/s write, to be raving about their new ASIC line which now boasts speeds of 120 MB/s read, 90MB/s write with a burst speed of 150MB/s and quicker access time of .1mb/s. This writer hopes to be testing the validity of these claims soon enough with the expected release date of their newest 32Gb ASIC SATA SSD set to be released in November. These claims are presently being questioned by Engadget, one of the more reputed sources for digital technology on the web.

Also a definite advantage is the sheer silence and lack of heat created through the SSD. I find myself, at times, waiting for the laptop to react, only to find its task complete and staring me in the face. We must also realize that, since there are no moving parts such as the hard disk spinning and being accessed, there is little to no heat generated by the SSD. This also now reduces the amount of time the fan is in use which, on my system, is virtually never. Again another bi-product of these positive attributes is the increased battery life gained through the lower power consumption of the drive long with the lack of fan use. Initial estimates thought these differences would be negligible but a quick glance at my first NBR article will surprise you I think.

To add to these, there are additional benefits of increased reliability as the the SSD is touted as being virtually crash proof as discussed by Samsung and having an unbelievable lifespan as shown here, once again by Mtron:



Am I reading this correct??? 140 years??? Wow!!!

Here are two videos to guide you through all the advantages of the SSD, the first by Samsung followed by Mtron. They are an excellent depiction of why the solid state drive is going to revolutionize consumer data storage alot sooner than we think.

What are Its Disadvantages?

Presently, there are three glaring disadvantages to the SSD, these being price, storage capacity and availability.

While we see prices dropping rapidly, one can still expect to pay upwards around $6-700 for the 32Gb Sandisk if its purchased on its own. You will find this easily doubled for the new Samsung 64Gb SSD and prices havent been released for the fastest SSD on the planet as claimed by Mtron, but its present 32Gb SSD (which is still well ahead of the pack) can be had for $1500US.

Size is then another consideration. We can run out and grab a 128Gb Super Talent SSD as seen here for around $4600 but the 64Gb is just entering the market with many people still fighting to find available 32Gb SSDs just to see if they stand up to their reputation. This brings us to our final point of availability of the solid state drive which is almost non-existant unless purchased through laptop manufacturers as they are presently rushing to get them out or watching Ebay.

On a further note, I have to credit Super Talent for their indepth article that they included above. Get a coffee for the entire 15 pages.

Ease of Transition

I am going to have to stick to personal experience here and limit myself to notebooks as I haven't had the pleasure of playing with a SSD in a powerhouse desktop as of yet (although I am interested hint hint). I have switched my SSD with a Seagate Momentus HD no less than 8 times now for testing. Further, I have had the opportunity to switch one SSD for another and can state that nothing could be easier.

Do you want an SSD? Simply find one, backup your system with a disk imaging program, pull out the HD and replace it with the SSD (both being SATA of course) and restore your system. Similarly, you can do a clean install just as easily as having the HD inside the system. There are no additional cables or carriages to worry about.

Further Reference

Are you interested in reading more about the SSD? You only have to go as far is this article within NBR to learn more. I have already mentioned the detail that companies such as Mtron, Samsung, Sandisk and Super Talent have placed into their own websites along with articles from Tomshardware.com and Anandtech.

Conclusion

The solid state drive has pushed in hard and fast and it's not going away soon. The SSD, muchlike the internet when it first came to light, was originally touted as a passing phase. It has quickly found a position where, if manufacturers can find the lower prices, higher storage capacity and availability, the SSD will threaten the mere existence of the HD. The first obstacle of performance was surpassed long before many knew what SSD stood for.

There appears to be so many benefits that we just cannot ignore the SSD on a business or personal use level. Although it will need to gain a foundation in the spiderweb designs of small and large office networks, the simplicity of the SSD lies in the absolutely lightning speed in which it accomplishes its tasks at the individual user level of both.

Quicker startup, incredible performance, no moving parts, less heat, longer battery life, incredible reliability and durabilty will soon enough conquer the obstacles of price, storage restrictions and availability.

Dont believe me? Look at this IBM 62PC "Piccolo" HDD, circa 1979 - an early 8" disk !!!

[frazell]

Doesn't flash memory have a limited number of writes? Somewhere in the range of 100K per memory cell? Doesn't that make your 140 years of use a little far fetched? Under heavy use it might last less than a traditional HDD...

SSD drives are sure to be here to stay in thin and light notebooks, but they are a very immature technology at the moment...

[Les]

Although its not possible to prove these in real life situations, expectations of all manufacturers are similar in that the comparison of write cycles bring the SSD way ahead of the HD for lifespan.

[Ice-Tea]

Two remarks:

* Please be write Megabytes as MB, not mb, which is generally used for Megabits.
*The reason why flash tech's limited number of writes is no objections is becasuse they use a wear levelling algorithm. Windows writes and reads to the same sectors over and over again and this would kill the drive in weeks if not for the fact that the drive will shift the data around even though the OS will never notice this.

[Les]

Thanks all for the vetting and information. It only adds to the article.

[powerpack]

Very nice. Looks like a sticky to me. I can't afford one yet, when do you see 100+GB happening?


Edit: I did not write well. When will we see at reasonable prices?

[Les]

Its happening as shown with Super Talent for quite the price. I have also read somewhere of a 320Gb SSD presently being tested.

And further to the question regarding lifespan above, here is Super Talent's take:

"The SLC NAND memory used in the SATA25 is typically good for 100,000 write/erase cycles, and Super Talent quotes drive life at greater than 140 years. Of course, like most mobile drives, the SATA25's warranty runs out in three years.

To help extend drive life, the SATA25 employs wear-leveling algorithms that spread write/erase cycles evenly across the disk to ensure frequently changed memory blocks don't fail before their neighbors. There is no limit on read cycles for SLC NAND Flash memory, so wear leveling isn't necessary for frequently read memory blocks—just those that are changed."

[frazell]

Originally Posted by flamenko

Its happening as shown with Super Talent for quite the price. I have also read somewhere of a 320Gb SSD presently being tested.

And further to the question regarding lifespan above, here is Super Talent's take:

"The SLC NAND memory used in the SATA25 is typically good for 100,000 write/erase cycles, and Super Talent quotes drive life at greater than 140 years. Of course, like most mobile drives, the SATA25's warranty runs out in three years.

To help extend drive life, the SATA25 employs wear-leveling algorithms that spread write/erase cycles evenly across the disk to ensure frequently changed memory blocks don't fail before their neighbors. There is no limit on read cycles for SLC NAND Flash memory, so wear leveling isn't necessary for frequently read memory blocks—just those that are changed."

Yea I'm just not convinced yet that it would last more than a few years for me, at least... I have standard HDs that have been in active use for over 6 years and are still going fine...

I'm reserving judgement of how long they last until we've seen them in long term usage. Manufacturers have these idealistic reliability projections that rarely translate into real world reliability. So all I'm saying is that long term reliability should be cited as a downside simply because the long term reliability of SSD is still out and there is no empirical information to backup what manufacturers are claiming...

Reminds me of recordable media... It is supposed to last 100-200 years... But only if kept in a super ideal state :P

[Jalf]

The problem with these wear-levelling algorithms is that they rely on data being moved around, and on there being enough free space to perform this wear levelling.

Imagine the disk is, say, 90% full with mostly static data (that never gets written again, just read). That means whenever new data is written, it has to go into the remaining 10%, which means those cells will be written to over and over. Of course, it could decide to move data from the other 90% into the last 10%, but that'd still involve writing to the same sectors.

Basically, I'm not convinced that this is enough to guarantee longevity in all cases. But it's too early to say.
Let's see when SSD's have been in use for a couple more years.

[villageman]

A good indication of reliability I guess would be the length of the warranty. Without moving parts any warranty of less than 5 years would be contradictory to their claims of 140 years.