Thanks for the detailed insight, i've added your comment verbatim to the report so it doesn't get buried. i'd plainly over-weighted on the GPE path it self and missed that this could also be happening completely. I've taken a bit of a deeper look as a result to both the SSDT/DSDT files and i saw that under _SB.TPM there's a SystemIO OpRegion at TSMI(SMIA,1) with an 8-bit SMI field and several _DSM case writes (SMI assert via the SMI command port im assuming), there's also an EXBU scratchpad with FSMI,ACPF,ALPR ... and so on which i assume is some kind of mailbox used bby the SMM/EC plumbling. Beyond that, I don’t see anything that would immediately stand out in the PEG* scopes themselves, would love to know your thoughts on this, here's the full SSDT/DSDT decompiled code: