TBW of a HDD

Khoomn · April 22, 2022

So I know for SSDs there is a maximum amount of TeraBytes Written to the drive. For my 1TB 860 Evo i think its 600TBW.

What I don't know is if there is a maximum amount of TeraBytes Written for a hard drive. I currently have a 5400 RPM 4TB Segate Barracuda Compute.

For the past few days I've been messing around with winhex, wipe, secure-delete, and eraser. Seeing how data can be over written and unrecoverable and seeing the limit to being able to revive a deleted file. Ive noticed that people say don't use those programs on SSDs as it puts a lot of wear on them. I currently just wiped a 2GB test file just to see what happened on my HDD and noticed it wrote about 70GB total to my drive (35 Passes on a 2GB File) and realized thats what people meant about wearing out an SSD.

Like I said before, I don't know if there is a maximum amount of TeraBytes Written that can be done to a hard drive of if you could technically just do unlimited amount of data

Dimondminer11 · April 22, 2022

40 minutes ago, Khoomn said:

So I know for SSDs there is a maximum amount of TeraBytes Written to the drive. For my 1TB 860 Evo i think its 600TBW.

What I don't know is if there is a maximum amount of TeraBytes Written for a hard drive. I currently have a 5400 RPM 4TB Segate Barracuda Compute.

For the past few days I've been messing around with winhex, wipe, secure-delete, and eraser. Seeing how data can be over written and unrecoverable and seeing the limit to being able to revive a deleted file. Ive noticed that people say don't use those programs on SSDs as it puts a lot of wear on them. I currently just wiped a 2GB test file just to see what happened on my HDD and noticed it wrote about 70GB total to my drive (35 Passes on a 2GB File) and realized thats what people meant about wearing out an SSD.

Like I said before, I don't know if there is a maximum amount of TeraBytes Written that can be done to a hard drive of if you could technically just do unlimited amount of data

As far as the amount of data written to a hard drive goes it is generally unlimited* but the * meaning that its only going to be able to be written to for as long as the drive still actually FUNCTIONS. It has no write limit where it'll die. HDDs just die generally from the actuator arm dying or the motor that spins the hard drive platters failing.

Needfuldoer · April 22, 2022

Spinning up and unloading the arm from its rest are the most stressful things a drive is typically asked to do. That's why datasheets for hard drives list both the number of load/unload cycles and the MTBF (mean time before failure) they're rated for. (And also why recertified used enterprise drives can be perfectly good, even with tens of thousands of hours worth of power-on time logged. If you pull the SMART data, you'll probably find they've only been powered up a couple hundred times. Contrast that with the drive in a 10-year-old desktop PC, which spins the drive down at every opportunity to try and save a few watts of power.)

As far as I know, the metal oxide on the platters doesn't "wear out" from just reading and writing. (All the drive has to do is flip a tiny grain of metal from one magnetic orientation to another.) It can certainly get corrupted, or suffer a manufacturing defect that only becomes apparent years down the road, but as long as those tiny metal grains stay on the platter they can be flipped back and forth pretty much indefinitely.

SSDs wear out because writing to NAND flash a slightly destructive process. SSDs work around this with their overprovisioning area (basically spare NAND flash to take the place of cells that die prematurely) and/or using SLC flash (which is more resilient than MLC, QLC, etc.) That's why they're rated by how much data gets written to them rather than by time.