Tuesday, January 5, 2021

Today I Learned: Shingled Magnetic Recording Hard Drives

Sometime during 2020, hard drive vendors have slipped SMR (shingled magnetic recording) drives into the consumer line of hard drive, that used to be only CMR (conventional magnetic recording). 

What's the difference? SMR writes overlapping tracks, instead of discrete tracks like in MMR. The result is MUCH higher data density, but much worse performance due to the need to micro-position the heads to read those overlapping tracks. With much higher density, what used to require more platters can now be made on fewer platters, reducing overall costs... as the expense of performance... something regular users likely would not notice. 

Previously SMR was only used on the VERY largest drives where they were advertised as archival grade: you write to it and mainly to store them rarely access them. But slipping them into the regular consumer channel means some people are buying them expecting them to perform one way... and they are not getting it. And some users are crying foul. 

Buyer beware... figure out if you have SMR or CMR spinning drives. 

Or just buy SSD. 

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