What is SMR HDD technology? Read this post to get the answer.

SMR, being the acronym of Shingled Magnetic Recording, is a kind of magnetic storage data recording technology used in hard disk drives. In fact, the SMR HDD technology is designed to providing more storage space on hard disk, without changing its size. In this way, the disk density is increased.

The most obvious difference between traditional data recording technology and SMR is – the former writes data into non-overlapping magnetic tracks (which are parallel to each other) while the latter writes new tracks overlapping part of the previously written magnetic track. As a result, SMR leaves the previous track narrower, so it allows for higher track density.

conventional writes vs. SMR writes

Pros And Cons of SMR HDD Technology

At present, the cloud storage becomes more and more popular; but for now, the local storage is still the most important data storage. This makes SMR a very promising hard disk storage technology. However, since it is not yet particularly mature, the SMR HDD technology brings us not only benefits, but also problems.


As we know, the conventional PMR (Perpendicular Magnetic Recording) has already reached its limit in storage space. Because of that, here comes the new technology – SMR; it changes the way how data are writing onto the hard disk drive, so as to improve the “disk storage density”.


Yet, the reliability of SMR varies. Besides, this new technology makes a qualitative change in medium structure; the read & write speed of it is actually decreasing. We can even draw a conclusion that SMR technology increases the disk storage density at the expense of overall hard drive performance. So, we think it’s like a transition technology to improve the situation currently, more than the solution to getting to the root of the problem.

Kind Remind: this post shows you an easy way to achieve better disk performance.

SATA 3.3 Optimizes SMR HDD Support

SATA-IO organization has upgraded the SATA 3.3 specification in 2016. The new standard brings some new features, such as remote power down function and optimized SMR hard disk support.

SMR is able to increase the HDD hard disk storage density by 25% when compared to the traditional PMR. Till now, Seagate, Western Digital and HGST have introduced many SMR hard drives. And most of the current hard drives with a single-platter capacity of 1.25TB are based on the SMR technology.

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