The closest thing which comes to my mind is this kernel config:
"Bus Options" \ "PCI Support" \ "PCI Express AMPS Control" \ "Default AMPS Policy" ---> "BIOS Default" / "Performance" / "Powersave"

I keep this at "Performance".
But I don't have this number in my aticonfig --odgc output.

However, this gentoo setup is highly unstable in many ways and levels. I am just trying to make it work because I had to get rid of Xubuntu asap.
For example, I have to run sgminer with --no-adl or I get segmentation fault. It finds 24 ADL devices for 4 physical cards. And my desktop is all black.