SMR hard drive performance

[pug_s]

Hi guys,

Some time ago I decided to schuck out an an 5tb hard drive from an external hard drive enclosure, and it has a model ST5000DM000. I used to have a old 2tb 7200rpm hard drive (I think it has 2 platters for got the model) but it performed fine. With this one, it took about 1-2 seconds more to boot up, I didn't really test the performance though. I also have an 4tb hard drive which I also schucked from a usb enclosure ST4000DM000. Both of the drives are similar in specs except the 5tb one was able to cram more data per platter due to SMR technology, but in your experience is it faster? Thanks.

 

[Solandri]

Shingled (SMR) drives should never be used as your main drive

The shingling technology relies on the read head being a lot smaller than the write head. The read-write head is essentially positioned at half-track (or smaller) intervals, but to do this the data that's written needs to be written all at once from the beginning of a grouping of tracks. The larger write head writes a full-size track, the heads are repositioned a half-track in, then the next track written which overwrites half of the first track. And so on.

https://www.seagate.com/tech-insights/breaking-areal-density-barriers-with-seagate-smr-master-ti/

The problem comes when you need to rewrite data. Because the write heads can only write a full-width track, it cannot selectively overwrite singled data. It has to erase the entire grouping of tracks and re-write them in shingled mode. This takes a lot of time, and you can lose data if you lose power during the process. SMR drives shingle groups of tracks (instead of shingling the entire platter), so a re-write only affects a small number of tracks instead of the entire drive.

Shingled drives are fine for backups, or for applications where speed is not important, or where you write a bunch of data and never delete it (media center drive). But avoid them for any other use.