i9 9900K stock, failing Prime95 stress test

Historically, my ritual for testing any CPU overclock has always been running a Prime95 stress test using the blend setting. I’d typically let it churn for somewhere between 9 and 12 hours, and if it managed to pull through without a hiccup, I considered the overclock rock solid. In my experience, I never encountered a single blue screen or system crash during daily use that suggested otherwise.

However, things have taken a rather frustrating turn recently. I installed a brand new i9-9900K into my rig, dialed in an overclock, and predictably, it threw an error after about an hour of testing. Thinking maybe I pushed it too hard, I reverted everything back to the factory default settings in the BIOS, but even then, Prime95 immediately starts spitting out errors again.

I’m honestly at a loss here; I’ve never dealt with a situation where a stock CPU paired with default BIOS settings would fail a Prime95 run. It makes absolutely no sense. What on earth am I looking at?

I've attached a screenshot for reference; https://ibb.co/3cxF4SP

The temperatures seem perfectly fine. Here are the full system specs:
Corsair Hydro Series, H150i Pro, 360mm Radiator, Advanced RGB
MSI RTX 3070 gaming setup
MSI Z370 gaming M5 8
Patriot Viper RGB LED, 16 GB Kit (2x8GB) 3000Mhz, black, PVR416G300C5K
Patriot Viper RGB LED, 16 GB Kit (2x8GB) 3000Mhz, black, PVR416G300C5K
Intel 660 1TB NVMe M.2 SSD, SSDPEKNW010T801
Seagate SSHD FireCuda 3.5" 2 TB, 7.200 rpm, ST2002DX002
Samsung 500G 840 EVO SSD
1TB HDD and 500GB HDD 7.200RPM
Corsair HX850i PC build
Corsair Obsidian Series 500D RGB SE Premium

Furthermore, since I swapped in the i9 9900K, my rig has frozen up at least once within a 24-hour window. It’s one of those complete system hangs where nothing works except a hard manual restart. I never encountered a single hiccup like this with my previous processor. I've already flashed the latest BIOS, so everything technically should be running perfectly, but clearly, reality isn't matching the specs. Does anyone have any insight into what might be causing this?

I’ll just run a 10-minute OCCT test, and if everything holds up, I guess that’s that. Honestly, I think you guys might be overthinking this. It probably won't give you any trouble during normal use.

Try testing with just a single RAM stick.

It’s not a direct comparison, but I had similar symptoms on my old junk rig after messing around with settings too much. Turns out the Windows installation was just corrupted. At least run an sfc /scannow

wiredotter14 said:Try testing with just a single RAM stick.

It’s not a direct comparison, but I had similar symptoms on my old junk rig after messing around with settings too much. Turns out the Windows installation was just corrupted. At least run an sfc /scannow

I've already tried everything under the sun and nothing has touched the problem, so at this point, I'm left with Windows as the primary suspect. My plan is to pull the current SSD entirely, swap in a different one, and perform a clean install of Windows to see if that clears things up. That way, I can always pop the old SSD back in with its existing OS if the chaos continues.

I went ahead and did another clean install of Windows 10, and honestly, it feels like everything is finally back on track—everything seems to be running normally again. I still need to put it through its paces with a bit more testing to be absolutely certain, but for now, things look pretty solid.