CSM turns on automatically in UEFI after shutdown

I just registered to say i am now having the same problem on my Z77Extreme4. Most of the time it doesn`t want to boot in UEFI mode any longer. It automatically switches from ultra fast boot to fast boot or gives me a error message that my graphics card doesn`t support GOP. I have tried both onboard and a GT 1030. I can`t find any info on this problem

kattepus wrote: Ok, seems like ultra fast boot doesn`t work if i turn on the PC before the monitor. Maybe the graphics are awaiting a connection with the monitor and fails to respond to the BIOS which then thinks it doesn`t support ultra fast boot? The PC is connected to a receiver and then to a TV. If i enable HDMI passthrough on the receiver ultra fast boot works even if the receiver is off.

The Ultra Fast Boot option of Fast Boot is really a fast, UEFI based POST. POST is shorter, so the overall startup or "boot" time is reduced.

With the monitor off, the VBIOS of the video card cannot complete the UEFI POST procedures. GOP is the UEFI graphics protocol, and if the test for GOP fails, you know what the result is.

It makes sense that HDMI Passthrough set on the receiver when it is off allows POST to complete. Otherwise any activity of the receiver's HDMI circuitry is communicating with the board.

kattepus wrote: Hmm yes, but my Z97 extreme4 boots correctly with monitor off. But not my Z77 Extreme4 or threadstarters Z270 systems (if it`s the same problem he is experiencing.)

Not to argue, but does each of these PCs use the the same video source? Each video card that is UEFI compatible has its own VBIOS, which may differ from model to model. Also, the Intel iGPU has a VBIOS that is part of the boards own UEFI/BIOS. We can find UEFI/BIOS updates for ASRock boards that include an update to the Intel VBIOS, the Z77 Extreme4 board certainly had them (I have two of those boards.) We can't see them anymore since only one non-Beta version is left for download.

My point is each video source's VBIOS may act differently in the situation being discussed here. One VBIOS may need the monitor on to complete POST, the other not. Do I know this for a fact? No I don't, but given the clues about this, it is certainly possible.

A question for anyone in the thread, although I know this will only apply to Intel 100 or 200 series chipset boards. Do any of you use the PCIe Remapping option in the Storage Configuration screen? Used only for NVMe SSDs in RAID arrays with Intel's IRST software. That requires the Launch Storage OpROM Policy option to be set to UEFI Only. Otherwise the NVMe SSD RAID array will not work.

I've been UEFI booting all of my PCs starting with my Z77 Extreme4 boards, one with an i7-2600K, the other with an i5-3570K. That is, with Windows 8, 8.1, or 10 installed with CSM set to Disabled. You can imagine I have at least one of every ASRock Intel chipset board since then, Z87, Z97, X99, Z170, and Z270 boards. All UEFI booting, CSM disabled.

Windows, when installed for UEFI booting, actually adds a legacy MBR system partition, for various reasons. That means it will still boot with CSM set to Enabled, with some exceptions. You should have four partitions on the OS drive, three others besides the main OS partition. That's the way all of my UEFI booting Windows installations are. They can boot with CSM set to Enabled, since Windows allows that to work. Unless your OS drive is a RAID array of NVMe SSDs, it should boot with CSM disabled, including the Launch Storage OpROM Policy option set to Legacy Only. If your PC does not boot with CSM disabled, and you are not using the PCIe Remapping option (Z170 and Z270 only) your OS installation does not seem to be fully configured by the Windows installer as it should be for UEFI booting. Or you don't have the Legacy booting entry in the boot order, only the UEFI booting boot entry, which is Windows Boot Manager. Some NVMe SSDs will Legacy boot (Samsung 950 Pro), but most if not all of the others won't. That does not apply to SATA SSDs.

I need to test this issue on my Z170 PC, which does not have a RAID array of NVMe SSDs. I'm using my Z270 PC currently, that does. But I need to get that PC working, which will take an hour or two.

The UEFI will automatically change the CSM setting, if it detects certain situations, such as being unable to UEFI boot, or selecting the Ultra Fast setting of Fast Boot with a Legacy booting Windows installation. Why that apparently does for some of you after simply turning off PSU is strange, none of my PCs do that. I work on them all the time, and I don't always clear the UEFI/BIOS, meaning I would reset the CSM option to Disabled when I restore a saved profile. That makes me wonder if something else is happening. Or the OS installation was not configured correctly. Very difficult to tell simply from posts in a forum.

I'm just trying to find out all the details here, since that is where we normally find the cause of an issue. I need to know what OS drive is being used, what UEFI/BIOS version is being used, mainly for older boards like the Z77 Extreme4, since they have added NVMe support and updated Intel VBIOS updates in later UEFI versions. Plus it is not quite the same to have CSM set to Disabled, or CSM set to Enabled and the Launch Storage OpROM Policy option set to UEFI Only. Some older video cards are not GOP compatible. The Intel iGPU has been GOP compatible since Sandy Bridge was released.

Yes, UEFI boot loads graphics drivers before OS and enables higher resolution on boot.