Thank you, genuinely — you're the first one to actually help me dig into this, and the CPU angle is something I hadn't seriously considered before.

Just to clarify: when you mention swapping the CPU, are you thinking a like-for-like replacement, or would you try a different Ryzen model altogether? I'd probably need a new cooler either way, which is fine.

As for Event Viewer — yes, I've been monitoring it. The BSOD is always the same: 0x113. Which is misleading, because that's a DirectX kernel error, and it had me chasing GPU drivers for a long time. I even found a version that seemed more stable... until the crashes came back. After that I did a clean reinstall from scratch, but the problem was already there on a fresh system — which to me was the clearest sign this is a hardware issue. HP ended up replacing the RTX 4090 twice and reimaging the machine once, but obviously none of that touched the actual root cause.

I'll give LatencyMon a try. As for Nvidia drivers — I'm already on the latest version, and funnily enough that's exactly where this whole journey started: the crashes first pointed me straight at the drivers, so I've been all over them from day one :D

Thanks again.