I recently started playing around with a bit of mining (though I don't think it will be something I do long term), and decided I wanted to try and drop my power consumption by undervolting. Afterburner was allowing me to select an offset for voltage, but it wasn't actually changing the value under load…and yes I made I the appropriate selections in the options. It's an XFX 280X that was showing 1.225v under load within Afterburner. With my custom fan profile I was mining at that voltage, 70 deg, and 67% fan speed.
I searched online and found it was a common issue with this GPU model and it looks like most of them are voltage locked unless you do a bios mod. That said, some people had luck changing the voltage using Trixx. I then uninstalled afterburner, installed trixx, and created the exact same custom fan profile.
Trixx still doesn't give me the option or ability to modify the voltage, HOWEVER, it is now showing the load voltage of 1.088, and temps are steady at 66 deg and 58% fan speed. GPU load is the same at 99% while mining, and Hashrates are the same.
Has anyone heard of this happening before? I would say it was an error in reporting voltage in one of the programs, except the temp drop and fan speed decrease support that the voltage has lowered. It seems to be stable, even after a gaming session, so I am happy, but confused.