Old ATI Mobility Radeon X1800, Adjust Voltage

I have xps m2010, it uses notebook graphic mobility radeon x1800. the card is so old that many of the recent GPU software can't seem to read it properly. GPUz was able to see core/memory clock and memory but unable to see temperature or voltage.

GPU meter/PC meter just fails to see it at all, not supported it seems, same goes for GPU monitor or GPU observer, cant see it.

however temperature shows up in Hwinfo but no voltage either. I was able to download ATItool and able to change it's core/memory clock speed but it doesn't have voltage control.

what I want to do is for it to run at a lower VID/clock when idle, something like CPU speedstep or nVidia powermizer. when idle, lower voltage, temp and clock speed, when used, back to highest etc.