In the era of Hard Disk Drives (HDD), disc fragmentation was the preferred tool to optimize the drive and speed up the computer. Old Windows versions even had fancy graphics, showing data sets on the drives being defragmented and allocated in a continuous area. For folks who had the time, disk defragmentation was a pretty engrossing experience.
However, things have changed over the years. HDDs are now being replaced with SSDs (Solid State Drives) that are much faster and don't have any mechanical moving parts. So, the question arises if disk defragmentation is still relevant for SSDs. Latest Windows 11 version continues to have inbuilt disc defragment feature, which kind of puts users in a dilemma. To understand if you should defragment an SSD, here are some important things to understand.
Software controlled memory access
In an HDD, the read/write head has to physically move to the specific area on the disc to access data. This takes time and even more so if data on the disc is in a defragmented state. On an average, mechanical drives can take up to 15 ms to access data. This could be higher in case the disc is badly defragmented. That is why defragmentation is quite useful in case of HDDs.
In comparison, SSDs do not have any moving parts. Their data access is controlled via software and they can quickly access data in any part of the drive. Their ability to randomly access data makes them faster. SSDs need just around 0.1 ms to access data, making them much faster than HDDs. As SSDs can quickly access data from any section of the drive, they do not require defragmentation.
Why Windows has defragment option for SSDs?
Windows does have automatic defragmentation and optimize option for SSDs. But it is there more for monitoring purposes, rather than actually defragmenting the SSDs at regular intervals. The defrag program may become active only if there are issues with the data stored on the SSD. However, that's quite unlikely. So, Windows continues to have the defrag option just as a precautionary measure. Users can switch off the automatic defrag option anytime they want.
What happens if you defrag an SSD?
If you want, you can defrag an SSD. It will hardly have any noticeable impact on performance of your PC. Rather than improving performance, frequent defragmentation of SSDs can actually shorten their lifespan. That's because every storage unit of SSD, known as single-level cell (SLC) NAND flash, has a limited number of write cycles. So, if you are defragmenting your SSD frequently, you could reduce its lifespan. It will still take several years, but why do things that have no real benefits.
As is clear from above, there is no real benefit of defragmenting your SSD. It may actually be harmful and reduce the lifespan of the SSD. On Windows, you can choose the auto defrag option or turn it off. By default, it is in ON mode. In both cases, there is unlikely to be any real difference in performance.