Speedstep works only with NullCPUPowerManagement.kext

[deeveedee]

Sierra runs well on my DIY desktop with old Socket 775 Gigabyte GA-G31-S2L motherboard (BIOS F10f). The system was recently part of my first learning experience with Clover and DSDT patching and has residuals from multiple failed attempts. HWMonitor shows that SpeedStep is working when I install NullCPUPowerManagement.kext (shows proper frequency switching and good temperatures); however, if I remove NullCPUPowerManagement.kext, the system boots and runs "fine," but CPU frequency stays at maximum and temps are high. All else appears to be working fine with and without NullCPUPM.kext.

I don't mind running with the NullCPUPowerManagement.kext, but if possible, I'd like to understand why this is the case and remove the kext if I can. My problem report files are attached.

Thank you for any help.

 

[deeveedee]

I was able to get SpeedStep working (without NullCPUPowerManagement.kext) by setting PluginType=1 in config.plist (Clover v4439). My system is as follows:

• Motherboard: Gigabyte GA-G31M-S2L (BIOS F10f)
• CPU: Xeon E5450 3GHz Quad Core 12MB Cache (Socket 771 -> 775 conversion, including microcode update)
• Memory: 4GB DDR2-800
• OSX: Sierra 10.12.6
• Mac Product: iMac 14,2
• Clover (Legacy): r4439
• Video: NVidia 8600GTS 256MB (NVidia WebDriver 378.05.05.25f07)