If you mean if it's possible to change the `VDDCOffset` in SCLKDependencyTable then yeah it is, the question is if the AMDGPU driver would honor it, I think it won't.
$ ./amdtweak --card 1 --read-card-pp --print
Card '1': {
... (omitted) ...
"SCLKDependencyTable": {
"RevisionID": 1,
"NumEntries": 8,
"Entries": [
{
"VDDC": 0,
"VDDCOffset": 0,
"SCLK": 30000,
"EDCCurrent": 0,
"ReliabilityTemperature": 0,
"CKSOffsetAndDisable": 128,
"SCLKOffset": 0
},
... (omitted) ...
]
... (omitted) ...
}
... (omitted) ...
}
So you can overwrite it through the script easily:
./amdtweak --card 1 --read-card-pp --set SCLKDependencyTable.Entries[1].VDDCOffset=-100 --print
I would like to add a more automatic solution to do undervolting, but that would take some time to do properly. I looked at the amdgpu driver and I was not able to figure out if it's using the voltage offsets or not. It seems it has no effect, but I'm not completely sure.