Machine: Lenovo ThinkPad X1 Extreme Gen 3, type 20TKCTO1WW
CPU: Intel Core i7-10850H (Comet Lake-H)
BIOS: N2VET26W (1.11), 2020-11-16
Intel ME: 14.0.36.1158
OS: Linux (Manjaro)
Goal: Re-enable CPU undervolting via throttled / MSR 0x150.
What I’ve confirmed:
- OC Lock bit (MSR 0x19b[20]) reads as 0 — the bit itself is
cleared - Despite this, all MSR 0x150 writes are silently discarded (no
error, writes just don’t stick) — the block is at
microcode/firmware level, not the MSR OC lock bit - throttled --debug confirms: CORE: -80mV → read 0mV — ERR (and
same for CACHE, UNCORE) - The relevant BIOS variable is CpuSetup, offset 0xDA (the
“Overclocking Lock” / voltage control gate) - Attempting to write it via setup_var 0xDA 0x00 in EFI shell
fails — the variable appears write-protected
What I’m requesting:
A patched BIOS with CpuSetup offset 0xDA set to 0x00 (disable
the voltage control lock), or alternatively a patched build
that removes the EFI variable write protection so setup_var can
do it in-shell.
I’ve attached a flashrom dump of my current BIOS below.
Edit by Fernando: Thread title shortened