SSD "Free Space" performance question...

[wsaenotsock]

If I recall it's good practice to maintain a free-space cushion of approximately 10-20% for optimum performance on an SSD. I understand that this free space could come from either an unpartitioned amount or an unused portion of a partitioned volume. But is this cushion number to be based on the total volume of the disk? Meaning -- if the user has many partitions, and one partition is full, there should be no issue caused as long as there is still free space as a total amount of the disk. Sound right? I have two 100gb partitions and one is full.

 

[Cerb]

Yes, the total disk, so long as you are either running TRIM manually, or using an OS+FS with TRIM support (such as Windows 7+, or Linux w/ EXT4 and the discard option). Though, for any SSD with a 2^nGB advertised capacity, or 60*nGB if Sandforce or an M500 (the extra reserved space isn't being used for spare area, like with a 840 Evo, 600, or Extreme II), 20% might even be on the lean side, at least for ideal performance.