How big is Host Writes on your SSD?

[Computurd]

(7500000000000 / (300 * 4096)) / 60) / 60 = ?
(7500000000000 / 1228800) / 3600 = ?
(6103515.625 / 3600) = 1695.42 Hours

OR 70.64 days of completely random IOs. (full span write ONLY)

Off by a little before cause I used 4k vs 4096. The specification has random write I/Os at 300/s using a full span.
The intel addendum lists their measured IOPs at 300 for 4k full span QD=32 random.
When you do limited span IO testing (say 8gb testfile) you get increased efficiency of coalescing and caching mechanisms resulting in increased performance. This is why the iops for smaller datasizes is much more, to the tune of 30 mb/s if i recall correctly.
If you are getting >10x the write speed then you are also getting at least 10x the coalescing. If they are getting 10x the coalescing then they are getting 10x the endurance.
An increase in spare area from 7% to 17% provides over a 2x increase in write endurance. This is directly from Intel. 10% spare area = 280% improvement in write endurance under most circumstances.
Think if he is using the drive basically empty.

EDIT: also you must realize it is Host writes. after write combining and the effects of NCQ from the OS there can be a tremendous difference between host and OS writes.