I tried the smartest you posted but, for my ssd it said that the test is not possible, i will post the photos of the same once i reach home.(currently on road)
Its a ssd sandisk 128gb.it is 3 years old.What kind of drive is the primary drive for that computer? Is it a spinning disk (HDD) or a solid state drive (SSD)? What specs does it have and how old is it?
Others above are right when they pointed out that drives (especially HDD) often show intermittent failures, which usually come just before the failure is not intermittent. (Extra credit to @Brickwizard for emphasizing it.)
Late edit: Noticed and fixed typo
It showed passed test 4 times, so i thought it was enough
In my experience any errors in the RAM will show up rather quickly.I did for 3 hours and there were no errors. I will try to run it for more than 8 hours tomorrow maybe i will get some hint.