SSD vs HDD: The Differences

Until quite recently, PC users had little to no choice when it came to file storage options that they received with a laptop or desktop. Your portable device usually came with a ‘spinning disk’ as the primary drive. Innovations in technology have given rise to the ‘Solid State Drive’ (SDD). But what are the differences between the two?

HDD and SDD: Cobwebs shed

Your traditional spinning HDD is the main source of storage on most computers. HDDs are basically metal platters combined with a magnetic layered coating. This coating stores your data, which could be your music, photos and work documents.

An SSD carries out the same job as the HDD just without the magnetic layered coating on the platter. Interconnected flash memory chips store the data, retaining it without the need for an active power source. The chips can be soldered directly onto a motherboard, via PCIe or through a traditional SATA disk interface. The flash memory chips are different from flash memory found in USB thumb drives by the fact of their type as well as the speed of memory. The flash memory in SSDs is quicker than a USB thumb drive’s flash memory, able to read and write at notably higher rates. This is one of the reasons why SSDs are usually a lot more expensive than USB thumb drives.

Advantages and disadvantages

SSDs and HDDs both carry out the same function: they hold the operating system, store applications, personal files and can provide backups of important materials. However, each kind of storage comes with its own unique set of features. Key question – what is the difference and why would users choose one over the other?

Price: SSDs are a lot more expensive than HDDs in terms of £/GB. A 256GB SSD typically costs £70 – £80 at the time of writing, whereas the same money could buy a 3TB (1000GB) HDD. This looks to remain constant for the coming years as HDDs are the older and established technologies and have more mature production lines.

Maximum capacity: SSDs reach a limit of 4TB, which are extremely rare and very expensive. HDDs have much larger maximum capacities of 10TB +. As storage capacity grows, the more data can be stored on a PC. While the cloud is a useful location to share these files with your various devices, local storage becomes a cheaper, faster option and only needs to be bought once.

Speed: Computers equipped with SSDs boot in seconds, rather than minutes. An HDD cannot match the throughput speeds, and the physical mechanics of a spinning disk can cause then to slow in time. PCs or Macs containing SSDs boot faster, launch apps faster and provide faster overall performance. An SSD upgrade can be a cost effective way of bringing new life to an old computer.

Reliability: Both storage types have their strengths and weaknesses. An HDD disk is sensitive to vibrations, sudden jolts and even noise! A spinning disk can be badly damaged if the computer or laptop is dropped or hit suddenly. The mechanics of an HDD also mean that components can wear or become misaligned over time, however most studies have revealed disks are far more likely to fail in the first few months due to manufacturing faults rather than age.

As SSDs are still relatively new technology, their weaknesses are still being discovered. It is widely known that each cell in an SSD drive has a maximum number of writes. To cope with this, the disk’s firmware spreads your writes across the disk evenly. Once a cell reaches its limit, it will be taken out of service and replaced with a spare (if available). In realistic terms, most people will have upgraded their disk or computer before this limit is reached. But it is worth considering if you have a particularly high level of writes in your workflow. From what we’ve seen so far, when an SSD fails the chance of data recovery is lower than a traditional HDD. The latter can be dismantled and the components recovered, whereas the former are sealed units with far fewer components to swap or repair.