At once upon a time 'stress testing' was taken into consideration as an added bonus when a computer (usually expensive one) was being considered or purchased. And perhaps more akin to the old days, than now?.
But it then became apparent, that 'stress testing' was just a practice of turning on the machine and leaving it on all day (if at all?), in the hope that something didn't fail. The failure of most computers is perhaps well known nowadays, and its a case of the item will or will not fail possibly some time in its life, whether that is in a few hours, years or never. Compatibility or configuration of parts is a different matter, but that as become more easier over the past years, with the increase of 'better technology'!.
There are a number of diagnostic or 'stress' tests that can be downloaded from the internet, and some of these are provided from manufacturer's or perhaps from eBay as 'Technicians Tools'.