Percent Lifetime Used vs. Total Host Writes

Bit Baby

Percent Lifetime Used vs. Total Host Writes

I have two M500 240GB SSD's set up as a RAID array. using CrystalDiskInfo, one shows:

- 92 "Percent Lifetime Used" (which measures % life remaing)

- 9.9TB Total Host Writes

 

The other shows:

- 59 "Percent Lifetime Used"

- 8.7TB Total Host Writes

 

The M500 spec is 72TB total writes.

How can the second have 59% life remaining with fewer host writes, and how can 8.7TB writes of 72TB limit equal 59% life remaining?

 

Thanks in advance.