Question Strange GPU behavior with ASRock "Ultrafast Boot"


Nov 29, 2018
System specs
  • Ryzen 5 3600 @4.15GHz, 1.325V
  • Zotac GeForce RTX 2070 Super Twin Fan (GeForce Game Ready Driver 451.67)
  • ASRock X570M Pro4 (BIOS version P1.40, AGESA
  • 2x8GB Gigabyte F4-3200C14D-16GVK @3533MHz
  • Windows 10 Pro 10.0.18362
Yesterday, I rebooted my PC after turning Hyper-V on and off, and it got stuck on the ASRock splash screen with the "VGA" light lit up on the motherboard. The only solution I found was keeping "Ultrafast Boot" off after clearing CMOS. All other UEFI settings were reverted to normal. I tried turning Ultrafast Boot back on after getting into Windows, and I had to clear CMOS again. The most recent changes I've made to my PC were a GPU BIOS swap 1–2 months ago so I could increase the power limit on my base model Zotac card along with the occasional driver update and Windows update. No issues that I can recall until yesterday. I don't understand how turning Hyper-V on and off could possibly relate to making my PC incompatible with Ultrafast Boot after 1–2 months of no boot problems and no significant changes to my setup.

Here's the really strange thing though: a few months prior to the GPU BIOS swap I did, I turned Ultrafast Boot on just to see what would happen. It saved a second at most from a 20-second BIOS time, so I decided at some point (could've been 1 day or 1 month after turning it on, I don't know) to turn the feature off because I didn't want to deal with any potential compatibility issues. Or maybe I was overclocking my RAM and had to clear CMOS which consequently turns Ultrafast Boot off. I forget. Regardless, something caused me to disable Ultrafast Boot, and this caused my PC to not boot with the VGA light lit up (completely blank screen, not the ASRock splash screen like I saw yesterday). The only way I could get into UEFI was by replacing the 2070 Super with an RX 550 I had laying around since the R5 3600 has no iGPU. I found that I had to turn Ultrafast Boot on to use the 2070 Super despite having the feature off without issues months before. At this point, I just accepted that my PC needed Ultrafast Boot on. I found many forum questions regarding issues turning different fast boot options on but none regarding issues turning it off. I have a feeling that the GPU is to blame, but maybe I'm just salty after spending $60 in shipping for an RMA when I first bought the parts for my PC.

TL;DR: I use my PC for a while without Ultrafast Boot with no issues, then I have to turn it on for my PC to work, then I have to turn it off for my PC to work. Lights on the motherboard indicate that there's a GPU issue.

I'll update this post after I install the latest BIOS updates and all that. Keep in mind that it took months for the boot issue I had yesterday to occur. Even if a BIOS update fixes everything, I'm still curious as to what could have caused the boot behavior I've experienced.