Now I have managed to sort out various hardware issues and have tightened RAM timings to get latency down a tad. my Ryzen 9900X is also running very nicely.I have 4 sticks of mixed Intel and AMD Corsair Vengeance and have managed to tweak the timings a little without raising the voltage as... More on forums.overclockers.co.uk

For daily OC stability I use Large AVX2 Extreme, and Small SSE Extreme. I run it for ~8 hours as a final test. If it hasn't thrown errors by then, it's very unlikely to happen after that. More on reddit.com

First, I think you're mistaking a stress test and a stability test. Occt is more of the latter, trying to detect errors that could be generated by your hardware. For that, there's no avoiding the "putting load on your components" part, that's true. You could avoid it in theory, but error detection would be so long it's basically pointless. You can remove from your mind that a computer that isn't stable under "unrealistic" load is stable under "less" load. If the stability issue is driven by power consumption or heat then yeah, it's true. It's false for everything else, from voltage issue to frequency issues and failing components. Most issues that arises when stability testing would arise under less load, it just would take more time for it to happen. OCCT small is a heavy test that doesn't go past the cpu cache. There's little applications to such programs out there, but it's basically the most effective way of testing your cpu for temperature and such. It's isn't unrealistic, it's designed to be extreme. OCCT large tests your whole cpu/chipset/memory components, and as such, is loading your components less individually. Yet, it is much better to find stability issues than small in practice for general purpose testing. Do not lessen a test to the power it draws or to the temperature the cpu reaches - a stability test will indeed reach higher temps than normal apps, but because a stability test reaches higher temps doesn't mean it is better. A good rule of thumb here is to use occt large with the highest avx instruction set your cpu/os supports. More on reddit.com

OCCT uses Prime95 as a base for the standard CPU stress test, if you run small data set and AVX2 on a 12/13th gen Intel CPU with unlimited power/current limit and sufficiently strong cooling to not throttle, you'll degrade the chip in a matter of hours More on reddit.com