3 ms·

That likely won't happen. Current SSD technology is quite limited in the number of writes, reducing the MTBF significantly.

by Cyph0n 11y ago

pkaye 11y ago
Per my parent comment, HDD technology is already starting to fall behind SSD technology in number of writes.
- Cyph0n 11y ago
  I'm talking about lifetime writes, not daily writes. If you look at the Samsung 850 PRO SSD specs page [1], the most important metric in SSD lifetimes is the number of terabytes you can write, or TBW. Yes, they do list the reliability in hours, but if you hit the TBW first, then it's game over. Reliability for the 850 PRO: > MTBF : 2 million hours(125GB/256 GB/512 GB/1 TB), 1.5 Million Hours Reliability (2 TB) TBW: > 128 GB / 256 GB : 150 TBW, 512 GB / 1 TB / 2 TB : 300 TBW So the 2 TB model can (theoretically) be used for up to 1.5e6 hours, but if you write 300 TB, it will simply fail. This is all due to limitations of NAND flash at the device level, so it's essentially unavoidable. There are primarily two different techniques for NAND flash storage: SLC and MLC. In SLC, you store 1 bit per flash cell, whereas in MLC you store 2 bits per cell. Due to the nature of MLC, you need multiple reads/writes to read/store data for each cell. As a result, SLC SSDs are much more reliable, but this comes at a higher cost. Most consumer SSDs are MLC or even TLC (3 bits/cell). See [2] for more info. [1]: http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd850pro/specifications.html http://www.samsung.com/global/business/semiconductor/minisit... [2]: https://itblog.sandisk.com/ssd-endurance-speeds-feeds-needs/ https://itblog.sandisk.com/ssd-endurance-speeds-feeds-needs/
poizan42 11y ago
I would think that mechanical harddrives will become a niche product for workloads requiring frequent writes in the not so far future. Also as large flash is getting cheaper it becomes more feasible to use a lot of it for over-provisioning to increase the lifetime.

That likely won't happen. Current SSD technology is quite limited in the number of writes, reducing the MTBF significantly.

by Cyph0n 11y ago

That likely won't happen. Current SSD technology is quite limited in the number of writes, reducing the MTBF significantly.

pkaye 11y ago

Per my parent comment, HDD technology is already starting to fall behind SSD technology in number of writes.

Cyph0n 11y ago
I'm talking about lifetime writes, not daily writes. If you look at the Samsung 850 PRO SSD specs page [1], the most important metric in SSD lifetimes is the number of terabytes you can write, or TBW. Yes, they do list the reliability in hours, but if you hit the TBW first, then it's game over. Reliability for the 850 PRO: > MTBF : 2 million hours(125GB/256 GB/512 GB/1 TB), 1.5 Million Hours Reliability (2 TB) TBW: > 128 GB / 256 GB : 150 TBW, 512 GB / 1 TB / 2 TB : 300 TBW So the 2 TB model can (theoretically) be used for up to 1.5e6 hours, but if you write 300 TB, it will simply fail. This is all due to limitations of NAND flash at the device level, so it's essentially unavoidable. There are primarily two different techniques for NAND flash storage: SLC and MLC. In SLC, you store 1 bit per flash cell, whereas in MLC you store 2 bits per cell. Due to the nature of MLC, you need multiple reads/writes to read/store data for each cell. As a result, SLC SSDs are much more reliable, but this comes at a higher cost. Most consumer SSDs are MLC or even TLC (3 bits/cell). See [2] for more info. [1]: http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd850pro/specifications.html http://www.samsung.com/global/business/semiconductor/minisit... [2]: https://itblog.sandisk.com/ssd-endurance-speeds-feeds-needs/ https://itblog.sandisk.com/ssd-endurance-speeds-feeds-needs/

poizan42 11y ago

I would think that mechanical harddrives will become a niche product for workloads requiring frequent writes in the not so far future. Also as large flash is getting cheaper it becomes more feasible to use a lot of it for over-provisioning to increase the lifetime.