Useful to leave a portion of your drive unpartitioned?

Shadowmoo

Honorable
Oct 17, 2013
3
0
10,510
When installing win 7 I left about 3gb on my SSD unallocated thinking this could possibly improve lifespan due to assisting in wear leveling. Is my thinking accurate in this? Does leaving a section of your drive unpartitioned assist in defrag and wear leveling for SSDs?
 
Solution
It probably depends on the specific wear-leveling algorithms used by your SSD.

An ideal write-leveler would keep tabs on pages that have been rarely (re-)written to periodically swap those out with more heavily worn ones and in this case, a spare partition would make no difference other than depriving you of 3GB extra space to work with since 3GB worth of rarely used files would get managed just the same as the spare partition would as far as the SSD's wear-leveling is concerned.

A less ideal write-leveler might rearrange pages only when an actual write occurs on them and pick less heavily worn pages when having to rewrite stuff. In this case, the extra 3GB may get under-used.

Defragging a SSD is usually not recommended since it...

namdlo

Honorable
Jun 20, 2012
451
0
10,860
You shouldn't be using "defrag" on an SSD - that's what the TRIM function is for.

All SSD have Over Provisioned (OP) space which is non-user space set aside. You should still leave additional user OP space though too.
 

InvalidError

Titan
Moderator
It probably depends on the specific wear-leveling algorithms used by your SSD.

An ideal write-leveler would keep tabs on pages that have been rarely (re-)written to periodically swap those out with more heavily worn ones and in this case, a spare partition would make no difference other than depriving you of 3GB extra space to work with since 3GB worth of rarely used files would get managed just the same as the spare partition would as far as the SSD's wear-leveling is concerned.

A less ideal write-leveler might rearrange pages only when an actual write occurs on them and pick less heavily worn pages when having to rewrite stuff. In this case, the extra 3GB may get under-used.

Defragging a SSD is usually not recommended since it wastes tons of write-erase cycles for little to no performance gain and for defragging, you would usually want to have the 3GB available in the partition your are defragging so files can actually get moved there during the process to reduce the number of times blocks of file data have to be moved back and forth. If you have a compulsive desire to defrag SSDs, schedule that only once every 2-3 months.

So my guess is on most SSDs, there would be few to no benefits to having a spare partition. At best, those pages get worn by write-leveling and degrade/fail at the same rate as pages in the main partition so you get no benefit nor disadvantage other than losing 3GB. At worst, pages belonging to the main partition wear out faster and you end up with a SSD operating in degraded state as its most worn pages get marked bad and replaced by less-worn pages from the spare partition.
 
Solution