Partition an SSD to only use half cells/capacity?


Limp Gawd
Jul 26, 2012
Is it possible to partition an SSD to exclusively use half of its physical NAND's and effectively double the drive life?

I have an unused 64GB SSD and I probably need less than 32GB or so for the OS and a few misc. programs. If there were smaller cheaper drives available at the time I would've bought one.

Nothing important will be on the drive that won't be backed up. If I can tell the drive to ignore half of its blocks then even when the first set I'm using starts to fail, as long as the controller and whatever other functional components are still good I can move to the other set and turn a 64GB SSD into two useable 32GB ones, theoretically?

I imagine it wouldn't be as simple as partitioning the drive during the OS installation, would it have to be done via firmware? Or is it just not technically possible given however SSD's work?
It is not possible. All the host computer can control is which LBAs are written to, but not which flash pages are written to. All SSDs will use wear-leveling to spread the writes out over all flash pages, even if you keep writing to the same LBAs over and over.

However, if you secure erase the SSD and then partition it to only half of its capacity, most modern SSDs should be able to use the extra flash (overprovisioning) in order to reduce write amplification, thus extending the lifetime of the SSD. Greater OP also usually helps with increasing worst-case write performance when the SSD is subjected to extremely heavy, continuous write workloads.
The drive life is going to be so long that it honestly isn't worth worrying about. You are going to want to upgrade a 64GB SSD long before you run out of writes on it, unless you are doing something non-standard with the computer (like running a database server or something).
SSDs don't really die from worn out NAND except in the most extreme use cases. I don't have the link anymore, but there was a group of folks on a forum running hardcore stress tests on a variety of SSDs, throwing a constant stream of writes, trying to kill them. Most of the drives tested went through several hundred TB of writes before eventually failing. That took many months, and was with 24/7 writing at maximum speed to these drives. Under normal use, you're going to get several years out of an SSD.
It was xtrememsystems, and they have a few drives up to thousands of TB at this point. I think the Samsung 830 was close to 4,000TB of writes.
If what you're suggesting was possible, it would more likely decrease the life of the SSD, not increase it, because the used half would be almost full and wear leveling far less effective. What will happen is that all the NAND will be used anyway, but since you won't be writing to half the LBAs, then the life will be increased thanks to wear leveling having lots of free space to work with.