Underclocking Memory Voltage Tahiti Cards (7950/7970/R9 280 (X))

[burundi]

Hi Community!

There is a good undervolting duscussion about the RX-Cards. Wattool can reduce the Memory Voltage. But what about the good old Tahiti-Cards. VBE7  (vBIOS Editor for Radeon HD 7000 series cards) doesn't have this feature. MSI Afterburner  has this Memory Voltage feature  but only for overvolting - lowest possible value is 1500mV

My questions:
1. Is there a bios-tool to adjust der memory Voltage?
2. Is it possible to modify the MSI afterburner to  downvolt the GDDR5?

BR,
B.