Okay. I was too hasty.
At the point I made my changes earlier, I was still using the new RAM. But, of course, resetting the CMOS did revert the XMP to disabled so it was running at its stock 2400MHz.
I’ve been gaming literally all night into the early hours of the morning without any crashes when it dawned on me I probably wasn’t running the XMP.
So enabled Profile 1 on this RAM which is 3600MHz and 18-22-22-39-1.35V
So quick game of Fortnite before bed because it always crashes the quickest and most consistently in Fortnite and indeed it does within 10 minutes or so.
I’m now doubting the settings I changed had any impact at all and it was disabling XMP that did it.
That being said, I did run the old RAM with XMP disabled and that was 2100MHz stock and I always got crashes with that too.
I will try again with this RAM and no XMP - the last working config - back with PBO set to Auto and see if that crashes and will report back. I guess that will answer the question about PBO being an issue or impacting the issue in some way.
After that, this RAM has another XMP profile 3000MHz 16-18-18-36-64-1.35V that I could try for good measure with/without PBO set to Auto.
Then I could try the original RAM with/without XMP and with/without PBO.
Update: 08:14am
So I feel like I've now confirmed that PBO and the Windows Power Options didn't actually change anything. So assume these are now defaults (PBO set to Auto and Windows Power Options set to Balanced).
But I do have some success with the Kingston RAM to a point where I had none with the Corsair RAM. Below you can see the results. Where the results are UNSTABLE games have crashed usually within 10 minutes of gameplay.
The important question(s):
What do we make of this, exactly? Is there something here that sticks out that would make the stable timings better than the unstable timings? What is causing the instability exactly? And at whose door does the fault lie? In my mind, issues like this should not be occurring so is it the sign of an underling issue that needs to be resolved? Or do I find the Goldilocks point with one set of RAM and just stick with it and can I be confident that I shouldn't face issues longer term?
Results of my testing below...
I haven't physically switched back to the Corsair RAM just yet but I can assure you multiple tests were done with the XMP profile disabled and it running at 2100MHz and this was unstable. I'll get the ZenTimings when I next swap the RAM.
But currently it goes like this:
STABLE
Kingston FURY Beast KF436C18BBAK2
XMP Profile Disabled (2400MHz)
Kingston FURY Beast KF436C18BBAK2
XMP Profile 2 (3000MHz)
UNSTABLE
Kingston FURY Beast KF436C18BBAK2
XMP Profile 2 (3600MHz)
Corsair Vengeance LPX CMK32GX4M2E3200C16
XMP Profile 1 (3200MHz)
Corsair Vengeance LPX CMK32GX4M2E3200C16
XMP Profile Disabled (2100MHz)
I'll get pictures later