Prime 95 with a version higher than 26.6 I generally run for less than a minute, just to see where VCore under AVX load lands with the LLC I set.

If you need to run Prime 95 for that long, run v26.6 - it doesn't use AVX and you won't be scraping 90C - if you're using 26.6 and scraping 90C you need a better cooler.

I usually stress test by running Intel Burn Test or Prime 95 (version higher than 26.6) for the crazy load, to check VCore voltage maximums with LLC set up...... For about 5 minutes. Then I just use the computer. If it doesn't hang during that, and I don't get a BSOD after a couple days of use, it's pretty stable. If I don't get a BSOD after a week, it's pretty damn stable.

In my experience, about half the time I can make a computer unstable during stress testing, but the other half of the time the computer hangs/freezes/crashes at 3AM idle or when I click some program, or when I'm just browsing Firefox.

I think the 6 core, 130w TDP processors are a different beast, because 90% of the time, if it's gonna crash because of CPU/Voltage, it's gonna do it on Windows boot up, with the little spinny dots.... If it's borderline unstable, those dots just stop moving.