Why the best choice is not always the cheapest when it comes to flash drives
Total cost of ownership (TCO) is a financial estimate that takes the purchase price of an asset and adds on the costs of operation over the period of ownership. When making a purchasing decision between various alternatives it is good practice to consider not only the item’s initial price but also consider how much will need to be spent on the item over its life, this is what is referred to as the total cost of ownership. The item with the lower total cost of ownership is normally the better value in the long run.
Clearly the importance of TCO varies depending on the costs structure. This calculation is more important for long term items or systems rather than consumables; if you are buying a loaf of sliced bread from the supermarket it is totally acceptable to simply look at the cost, but if the purchase involves a piece of equipment, such as a central heating boiler, then there are many other factors to consider and the calculation becomes more complex. For example, if a more expensive boiler uses less fuel and is more reliable there will likely be a saving in repair costs, so it may well have a lower total cost over its operating life than a cheaper option. There are other factors to consider in relation to reliability; the cost of failure could be more than just the cost of repair if it involves a loss of earnings.
When making a calculation it is important to consider all costs, from the initial integration of the part into a system to the ongoing operating costs such as power, maintenance and repair, and even the cost of replacement if relevant. From these figures, particularly in an industrial environment, the actual purchase price is only a tiny portion of the total cost. In a production environment, the total cost of one failure could easily be higher than the purchase price, but surprisingly perhaps it is often still just the initial purchase price that is used for comparisons.
Counting the cost of failure
When we consider the use of Solid-State Drives (SSD) the TCO calculation is even more important. We are amidst the age of the Industrial Internet of Things (IIoT), where the collection and analysis of data has become a key business driver. In the past, data was simply used to monitor and assess the industrial process, so any loss would have a marginal impact. But in the age of the IIoT, where machines are connected to make up systems of systems, the amount of data recorded has multiplied exponentially and its value to the process greatly increased.
By collecting, learning and analysing this data, the production efficiency of industrial processes can be greatly improved. As the intelligence of a system becomes inherently dependent on the interconnectivity of devices, the downside is an increased reliance on huge volumes of data, such that if one component should fail it can have cascading and costly consequences, reducing operational efficiency or even halting production. Downtime in an industrial environment can cost thousands, or even tens of thousands every minute. All this because of the failure of one critical element like a flash drive somewhere in the system.
In the modern age, machine learning is core to this efficiency and each component in the system has learnt from the data amassed to maximise efficiency, which means that replacing a component is not as straightforward as it was in legacy systems. Much like adding a new human into the mix, a new machine or component will take time to learn and get up to speed.
One way to mitigate this risk is to constantly back up all the data accumulated, but this comes at a high cost. A more practical and cost-effective strategy would be to ensure that the flash memory products offer industrial levels of reliability, able to meet all the demands made on them over the lifetime of the system. The upfront cost may be higher but when compared against the cost of failure or constant back ups it will make strong economic sense.
Counting the cost of energy
The cost of operation for flash drives is often a factor that garners very little attention. Even though in consumer PCs an SSD consumes only about a third of the power of a HD, it is not often a consideration for the user. However, in industrial environments or data centres, that saving is multiplied by hundreds or thousands of units and so it becomes much more significant. Thermal management in datacentres is now also a challenge, particularly when you consider that dissipating every 1W of heat generated requires 2W of cooling power.
Hyperstone´s flash memory controllers use the latest technology to consume as little energy as possible. In the X1 SATA controller, we use a total of four power modes (three sleep modes) plus the option to dynamically switch off so-called power islands during periods when the logic of that region is not used. This ensures that the controller and therefore the drive consumes as little energy as possible. Another relevant aspect to consider is the impact of power on the runtime of mobile devices; while the power requirements of flash drives in devices powered off-line might only be measured in terms of the cost of energy, power will have a big influence on the runtime of a battery powered device.
When considered holistically, the total cost of ownership becomes a vital consideration when designing a product or system. Spending a bit more at the outset can reap huge rewards in operating costs, avoiding failures and ensuring that devices are trusted and valued by the industries they serve.