Solid State Drives are all the rage and many computer enthusiasts are looking forward to getting one SSD or more for their own machine for the significant improvement they can gain from these high-speed drives. And below you will acquire the basic knowledge you need to grasp as an ordinary computer user.
An SSD (Solid State Drive) is basically a flash storage device, which is the next generation equivalent of an HDD (Hard Disk Drive). Where they differ greatly is an HDD contains spinning magnetic platters which are read and written to by heads floating on a cushion of air along a series of guides known as ‘actuator arms’, while an SSD contains no moving parts, and instead of spinning platters uses a special type of memory known as NAND flash.
Now, you might say that this type of storage already exists in the form of flash memory drives that plug into the USB port. This is partially true as solid state hard drives and USB flash drives both use the same type of non-volatile memory chips that retain their information even when they have no power. The difference is in the form factor and capacity of the drives. While a flash drive is designed to be external to the computer system, an SSD is designed to reside inside the computer in place of a more traditional hard drive.
So how exactly do they do this? Well, an SSD on the outside looks almost no different than a traditional hard drive. This design is to allow the SSD drive to put in a notebook or desktop computer in place of a hard drive. To do this, it needs to have the standard dimension as a 1.8, 2.5 or 3.5-inch hard drive. It also uses the common SATA interface so that it can easily be placed into any PC as a hard drive would.
The Advantages Of Using An SSD
Solid state drives have several advantages over the magnetic hard drives. The majority of this comes from the fact that the drive does not have any moving parts. While a traditional drive has drive motors to spin up the magnetic platters and the drive heads, all the storage on a solid state hard drive is handled by flash memory chips.
So let’s look at the most important advantages of an SSD compared to an HDD.
- The key advantage is that they are much faster than an HDD.
- They contain no moving parts, so there is no mechanical wear.
- Silent, as the contain no mechanical parts.
- Produce next to no heat at all.
- Consume much less power compared to an HDD.
- Robustness. Drop an HDD onto the floor and the chances of it still working are remote. Drop an SSD, and unless you are very unlucky, the SSD will not be damaged and should continue to function normally.
- An SSD has very much faster access times compared to an HDD.
- An finally, they have much greater data throughput than an HDD.
But these advantages can be abridged in just three major distinct ones:
- Less Power Usage
- Faster Data Access
- Higher Reliability
The power usage is a key role for the use of solid state hard drives in portable computers. Because there is no power draw for the motors, the drive uses far less energy than the regular hard drive. Now, the industry has taken steps to address this with drives spinning down and the development of hybrid hard drives, but both of these still use more power. The solid state hard drive will consistently draw less power then the traditional and hybrid hard drive.
Faster data access will make a number of people happy. Since the drive does not have to spin up the drive platter or move drive heads, the data can be read from the drive near instantly. Hybrid hard drives do tend to mitigate the speed aspect when it comes to frequently used drives. Similarly, Intel’s new Smart Response Technology is a similar method of caching on a small solid state hard drive to produce similar results.
Reliability is also a key factor for portable drives. Hard drive platters are very fragile and sensitive materials. Even small jarring movements from an impact can cause the drive to be completely unreadable. Since the SSD stores all its data in memory chips, there are fewer moving parts to be damaged in any sort of impact. While mechanically SSD drives are better, they do have a limited life span. This comes from a fixed number of write cycles that can be done on a drive before the cells become unusable. For most consumers however, the write cycle limits tend to still allow the drives to last roughly five years or more which is longer than the average computer system.
But there are also disadvantages of SSDs, which are:
- Price per gigabyte of data storage, an SSD is more expensive than an HDD.
- If an SSD is going to fail, it will tend to fail without warning, whereas an HDD will tend to give warning signs before it eventually fails.
- Buggy firmware. Because SSDs are a new technology, the pace of development is high. This can lead to SSDs appearing for purchase that still have some firmware bugs which need to be worked out of the system. However, this does tend to be rare.
There are various types of NAND available but as enterprise grade NAND is currently much more expensive, for consumer grade SSDs, the type of NAND flash used is MLC (Multi Level Cell). MLC NAND is able to store 2 bits of data per cell, and each cell has four possible states. MLC NAND is used in consumer grade SSDs in order to the keep the costs down.
So what is it that makes an SSD so much faster than an HDD?
As I mentioned above an HDD has spinning magnetic platters to store the data, and that data is read or written by a series of read/write heads. Each platter has its own head, and the head is moved from the outside of the platter to inside of the platter by the slide actuator assembly. The head can only be in one place at any one time, and it takes time to move that head from one location to another. Even if it’s only a 1mm away, it will still take a few milliseconds to move the head before reading or writing can recommence.
An SSD reads and writes its data from NAND flash, and it’s not uncommon for the SSD controller to have eight channels to transfer data to and from the NAND. Also the time taken to access the data can be 100 times faster than it is on an HDD. So as well as being capable of 8 times the throughput, it can also access the data much faster than an HDD.
Why Aren’t SSDs Used For All PCs?
As with most computer technologies, the primary limiting factor of using the solid state hard drives in notebook and desktop computers is cost. These drives have actually been available for some time now and have come down dramatically. Drives are finally reaching the $1 per gigabyte price mark that makes them more feasible for consumer use. Mind you, this is still ten times the cost of a similar hard drive technology so it still has a high cost.
Capacity is also a major factor in the adoption of solid state hard drives. The average notebook computer equipped with a SSD will have around 128 to 256GB of storage. This is roughly equivalent to what laptops of several years ago came equipped with. Today, most laptops feature 500GB or more of storage with a hard drive. Desktop systems have an even greater disparity between SSD and hard drives as the average desktop comes with 1TB or more of storage.
Even with the huge difference in capacity, many people are finding that most computers have far more storage capacity than they typically have. Only a large collection of raw digital photo files and high definition video files will likely fill up hard drives quickly. As a result, solid state hard drives will generally offer a sufficient level of storage for most laptop computers. Additionally, high performance external options thanks to USB 3.0, eSATA and even Thunderbolt make adding extra storage space with an external hard drive quick and easy for non-essential files.
The bottom line.
An SSD still represents the biggest bang for buck PC upgrade. When you upgrade from an HDD to an SSD, the difference in tangible performance is massive. Every application or game will benefit from loading from an SSD. Video editing becomes as smooth as silk, as data is cached in and out of the SSD, and as a system drive, an SSD is untouchable.
The price of SSDs has at last dropped to a level that most people should be able to afford one large enough to use as a system drive.
The future of SSD looks very bright, and while the prices are dropping down and SSDs are getting cheaper, it will be a wise decision to give it a try to enjoy its great performance it can provide to your computer
To read more about SSDs, I would rather you download “Top 20 Things To Know About SSD” document from Seagate.com