The State of Solid

It doesn’t seem so long ago that Solid State Drives (SSDs) were a thing of dreams. The idea of storing data permanently in solid state memory - which is effectively the same technology as that used for RAM - was very appealing but seemed ridiculously optimistic. And now, here we are in 2019 specifying and supplying 4TB SSDs as regularly as we once did 9GB SCSI drives, less than 20 years ago!

What’s so good about SSDs?

Speed. That’s what’s good.

Here’s a rough idea of the difference in sustained transfer rates for HDDs and SDDs, along with the capabilities of various computer interface protocols.

Approximate sequential read rates / transfer rates in Megabits per second (Mbps)

You’ve probably noticed that the SATA SSD (which is the type of SSD you’re probably most familiar with, featured in most external SSD solutions) is still not all that fast compared to the transfer speeds available in even the oldest of computers (even the late Apple G5 had PCIe 1.x slots). That’s down to the SATA interface - the same one that has been used for all types of drive for the last 18 years or so. Whilst being able to attach your new SSD to the same connector as your old HDD is very convenient, its relatively low transfer rate of 6Gbps doesn’t allow manufacturers to take advantage of the real potential of solid state technology.

What’s Next?

The future is in the types of flash drive that are featured in most new Apple computers now. These NVMe (Non-Volatile Memory Express, if you must know) drives interface directly with the host computer’s PCIe buss, which, as you can see from the chart above, gives huge potential for much, much faster transfer rates.

When can I get one? I can’t wait!

Whilst mainly utilised internally right now, new devices are available right now, that provide Thunderbolt 3 access to NVMe drives, and the price isn’t as high as you might think.

Bear in mind that transfer rate isn’t everything. For audio systems, where multiple small files are being accessed simultaneously, the increase in “Input / Output Operations Per Second” (IOPS) associated with all SSDs is so much higher that the bar for the HDD doesn’t even register on the scale:-

Input / Output Operations Per Second

The figure for the HDD is just 100; 1,000 times lower than even the SATA SSD.

So don’t hang back - SSDs will change your life!