Clover overwriting VCore settings?

I've been running my current setup since 10.6 in 2010, using the iMac 11,1 system definition with Chameleon/Chimera. GA-P55A-UD4P board, i5-750 overclocked to 3.2GHz with turbo enabled. I'm using the edited DSDT for this board downloaded from this site.

I decided to try a Clover installation on a second SSD and after a rough start i've got it booting into 10.10.4 and running mostly fine (Turbo works, sleep and SpeedStep down doesn't)

But whenever I reboot from the Clover drive back to my "main" Chimera+10.9 installation, the VCore setting in my BIOS gets reset back to "Auto". Normally, I have it manually set to 1.375v as that seems to be the most stable value for my CPU, allowing it to turbo all the way up to 3.8GHz no problem. But with VCore at "Auto", my machine will usually lock up during or shortly after boot.

The strange part is that none of my other settings in the BIOS are altered, only the VCore is reset. Has anyone else ever seen an issue like this? Is booting with Clover allowing things to access the BIOS in a way Chimera wasn't, and if so, how do I prevent it from resetting?

Worst case scenario I'll just keep sticking with Chimera, but since Clover seems to be the wave of the future and doesn't require any kext rollbacks, I figured I'd give it a shot.

Clover config.plist is attached. I'm using the latest Clover r3241, installed to the EFI partition. I tried both SATA and BIOSBlockIO variants but they each exhibit the same behavior.

Clover does modify a UEFI BIOS, not sure about non UEFI bios though and don't know why it's modified your V-Core setting.

Question? did you start off with a native DSDT.aml (unpatched) or an already patched DSDT?

The reason why i ask is because you have a DSDT.aml with lots of Clover DSDT fixes applied.
Fixes should be applied to a native DSDT and not applied to an existing patched DSDT.

Anyway, I've edited your config.plist as follows;

• Removed KernelPM flag - that's for Haswell not P55)
• Removed Drop OEM (SSDT section) - use that flag only when using a custom SSDT (but not if using DropTables)
• Added Drop OEM_DSM (DSDT section) - needed when using a custom DSDT
• Removed AppleRTC because your patched DSDT.aml deals with that (re-apply if your DSDT hasn't)
• Removed Rootless=0 - unless you're booting OSX El Capitan with patched kext(s), it's not needed
• You can uncheck Debug flag for faster boot times (though i've left that alone)

hope that helps..

Thanks for the tips!

I'm using the DSDT for the P55A-UD4P (F14 BIOS) downloaded from http://www.tonymacx86.com/dsdt-database.php

I'll give it another try with your config and report back.

I disabled all of the redundant fixes and made the other recommended changes. Boots up fine, thanks again for helping me trim it down.

By monitoring with HWSensors I see that the manually specified vcore is applied correctly if I've just gone into the BIOS and set it, but shutting down or rebooting from the Clover Yosemite install sets it back to "Auto". Shutting down or restarting from Chimera Mavericks or Windows 7 preserves the settings.

Maybe I should try a different build of Clover and see what happens.

Hey darukaru,

glad you trimmed down your config.plist since your patched DSDT.aml should already contain those fixes. It's best to start minimal with your config.plist and only add what's relevant/needed. I have no Clover DSDT fixes on my config.plist, just boot flags, my patched DSDT and my custom SSDT

Your V-Core setting issue has really stumped me and i couldn't find anything on google. I know that i do not use the Asus AICPUM flag on my config.plist as that flag is only needed for motherboards with a locked MSR and Gigabyte mobos have a unlocked MSR so you could try disabling that and see if it boots without it.

I would expect that a P55 motherboard has a Legacy BIOS so i expect that you're using Legacy settings for Clover i.e,

• Install Clover in ESP
• Install boot0af in the MBR
• Theme (your choice)
• Install RC scrips on target volume

if not then try those above settings

If problem still exists, then i would backup your current BIOS and flash to the previous BIOS version. Try that with the corresponding DSDT for that previous BIOS version and see if it solves your problem?

Good Luck

I never did figure out what was going on with this. I think what I'm going to do is hang onto 10.9/Chimera for now and just save up for a Skylake setup once El Capitan supports it natively.

Did you ever solve this issue? I just played a bit around with my old P55 rig (i5-750 as yours) and I have a similar problem:
After every sleep/restart/shutdown some settings are set to AUTO, which results in an unstable and/or dangerous setup.

In particular:
- VCore = Auto, which defaults to very high voltages (a lot more than necessary for stability).
- IMC voltage = Auto
- Memory Multiplier = Auto, which defaults to x10, thus running my memory way beyond specification
- Core PLL = Auto, so it'll unnecessarily be increased

This is a super late reply, but no, I never did figure it out. I eventually just reverted back to 10.9 and Chimera and stayed there. The 10.9.5 security updates have caused the occasional weirdness: somewhere along the way, I lost SpeedStep down but Turbo up still works.

I just ordered a Z170 setup and will start fresh with El Cap on that. Once I get the new system stable, I might turn off the OC on the P55 board and try to get it running 10.11 and/or just put it out to pasture as a file server.

Hey there, i have a similar issue with Mojave on an Aorus Master Z390 and i9900K (i have a thread about it). Any thoughts?