Hi, I've attached a patch that adds preliminary access to the HID1 register in the 750GX (aka the PLL config register). The patch is against 2.4.30. It has been lightly tested on a PowerMac 8600 with a PowerLogix PowerForce 750GX cpu card. Depending on the values for the pllx_cfg field, this should work on the 750FX as well ... except for the stuff in idle_6xx.S. Since there are plenty of people on this list way more smarterer than me I was hoping someone could answer a question about the powersave modes that some of the PowerPC processors have: Since, as I understand it, the clock is shut off to much of the chip when a powersave mode is engaged does it really buy you that much to switch to a lower clock speed? Wouldn't you be better off shutting off the unused PLL? Also, please note that I am not very experienced creating patches so please use a backup of your source tree. kevin