Comparing Solid State Drives to Hard Disk Drives
When comparing SSDs to HDDs you have to make certain allowances. Traditional HDD benchmarks are focused on finding the performance aspects where they are weak, such as rotational latency time and seek time. Since SSDs do not spin, or seek, they may show huge superiority in such tests. On the other hand, SSDs have challenges with mixed reads and writes, and it is entirely possible that their performance may degrade over time. To get a more accurate comparison, you should test an SSD once is it filled to capacity with data. This is because a new and ‘empty’ disk is likely to show a much better write performance during the test than it would show after years of use.
Some of the advantages that SSDs have over their HDD counterparts are that the former has a faster start-up than the latter because no spin-up is needed. SSDs also have faster random access because of the absence of seeking motion which is a characteristic of the rotating disk platter, the read and write heads and the head-actuator mechanism of HDDs. SSDs also have more consistent read performance because the physical location of the data is irrelevant. They also feature faster boot and application launch time. SSDs are also less susceptible to file fragmentation because unlike HDDs, they are not subjected to data access degradation caused by the greater disk head seek activity when it tries to find data that is spread across many different locations on the disc.
SSDs are also generally a lot quieter in operational mode because unlike HDDs they do not have any moving parts. This is also the reason why they are much cooler running, consume less power, have much higher mechanical reliability and are able to endure greater shock, vibration and temperature ranges and are able to operate at higher altitude. SSDs also tend to have around double the data density of HDDs and eliminate the need to defragment the disc from time to time.
On the flip side, SSDs with flash memory have a relatively limited lifetime and can wear out after around 2 million P/E cycles. The life of the device can be extended by adopting special file systems or firmware designs that can mitigate this problem by spreading the writes over the entire device. This technique is known as wear leveling.
At the time this was written, HDDs are being sold at a lower cost per gigabyte than SSDs. This being said, SSDs are closing the gap quite quickly and at the current rate, they are expected to be price competitive with HDDs over the next few years.
How All This Relates to Music
What does all this mean for music listeners? For starters, the ever-decreasing cost of storing data is proving to be a boost for the sales of high-resolution music files, especially 24-bit/192 kHz resolution files, which are exponentially larger than their CD-quality 16-bit/44 kHz counterparts. The shrinking size of external drives is making it a lot easier and more convenient to store and carry around your music files. Today you can buy 256 gigabyte thumb drives which can probably store your entire music file collection and carry it around in your pocket.
This trend is also expected to hasten the CD system’s journey into extinction. Just a couple of decades ago we marvelled at how the CD system made it so easy to store and access our music. We now live in an age where one jump drive that fits into the palm of our hand can contain the same digital music content as hundreds of CDs!