So yeah. This isn't the most brand spanking new thing I'm having a problem with today. More like my 5 year old system that's causing headaches.
I decided to flash the bios to the latest version yesterday (mostly 'cause I hadn't done it in a while... ahem... an eternity), and because I figured it might actually solve one or the other stability issues I have been facing every now and then.
So I upgraded from bios v1801 to v4001 (yes, there were a few years and iteration in-between).
Interestingly, I was able to get pretty much all my overclocking settings as I previously had... but... IMPOSSIBLE to run the DDR4 at its rated speed.
It would either go straight to code B7, or just cycle to bd a few times and end up giving up in CC (mobo status codes).
The highest frequency I was able to boot at was 2400. No matter what strap, bclk and divider I chose.
I started to think the ram might just have unseated itself, or got damaged in the bios flash... But then I flashed back to bios 1801, re-applied my profile and bam, XMP loads, 15-15-15-35 1T @ 3200 boots and loads without a glitch.
After that I tried v4101 again, triple-checking I was running the exact same settings... but again, same crapping out above 2400 MHz.
Is there a rational explanation as to why the new bios(es) won't allow the ram to work properly (anymore)? I'm staying on my (vulnerable) v1801 until further notice I suppose. Can't live with having a water-chilled top-of-the-line (2015 edition) PC with gimped DDR4.
Some builds can simply favour certain CPUs over others, as no two CPU are identical. If the system was working fine on the previous build, it's safe to leave it. Or, you can dial out the instability manually.
Any time Ive changed the BIOS and had adverse effects I just roll it back. I normally pay the extra for the boards with dual BIOS so I can switch back using alternate BIOS ROM first before rolling back the other.