Flash drive per-gigabyte (GB) prices have dropped by more than 10% since March 2023 to an average of $0.075/GB this week. That’s down from around $0.09 per gigabyte six months ago. At the same time, spinning disk hard drive per-gigabyte prices have largely remained static, at $0.05/GB for SAS and $0.035/GB for SATA drives.
Those figures are the result of exclusive analysis by Computer Weekly that gathered drive prices weekly from Amazon.com as aggregated by diskprices.com. Over the course of 28 weeks, more than 17,000 drive prices and specs were gathered, with averages calculated every week for triple-level cell (TLC), quad-level cell (QLC) and multi-level cell (MLC)/unspecified flash drives, as well as SAS and SATA spinning disk.
The figures show the price differential for flash drives and spinning disk narrowing over the six-month period.
The analysis used diskprices.com’s aggregation of new drive prices on the Amazon.com site, with an average of more than 600 prices and specifications gathered per week. Data was filtered to take account of the different flash and spinning disk types and average price per gigabyte calculated per week for each of them.
Data is for drives that range in capacity from less than 1TB (terabyte) to 22TB (hard disk drive/HDD) and 8TB (solid-state drive/SSD), with an average of 3.6TB per drive offered for sale.
Price per gigabyte for all three flash drive types dropped over the six-month period, while spinning disk HDD prices remained at similar levels. That movement shows the long-term trend predicted – and indeed hoped for – by flash storage array makers of a scissor effect as flash becomes competitive in price by capacity terms with HDDs.
While the analysis is based on Amazon prices, the volume of data gathered does show trends in pricing available to smaller businesses and consumers.
Price per gigabyte is a major consideration for customers that potentially have many terabytes of capacity to plan for. It is not the only factor in procurement calculations, however. Total cost of ownership over a drive’s lifecycle also comes in to play, with purchase cost, energy and maintenance key among them.
The jury is still out about whether flash drives are always more efficient in energy terms. Calculations by Computer Weekly demonstrate that it really depends on the make of drive chosen.
Spinning disk has moving parts and so generally draws more power than solid state in all states of operation, namely several watts during reads and writes and not much less when idle. Flash’s working power draw is often similar or even in excess of HDD, but less when idle.
Flash can win out, however, when it comes to density of storage as capacities increase.
Flash will also cost more per drive to buy than spinning disk, but maintenance costs are likely to be lower. Cloud storage provider Backblaze – which publishes annual reliability figures for the hundreds of thousands of drives in its estate – found its SSD lifetime annual failure rate was 0.9% in mid-2023 compared with 1.45% for HDDs.
Some storage suppliers claim much better price per-gigabyte costs than for off-the-shelf drives. Pure Storage, for example, builds its own drives with much greater density than those available from the big drive makers and so claims better cost per capacity.