[DSDT] Vanilla Speedstep - no _cst evaluation errors

[FKA]

Hi

 

This is a very rough and ready guide to achiving vanilla stepping by patching DSDT.

 

The guide assumes you have prior experiance of patching DSDT

 

This is not my method and has been learned from the various DSDT topics. I hope to bring some of that information together in one post.

 

Firstly you will need to have extracted DSDT and SSDT tables. This can be in Linux or the total noob method - boot into windows and use Everest. Both methods outlined in this thread here

 

The basic idea is to add SSDT tables to the end of DSDT using this method here and then edit the _PSS tables to give your desired stepping.

 

Using the same method I added _cst (c-states) SSDT tables from MacPro3,1 (as my MB does not have any!) These tables are posted by roisoft in post #70 here

 

I then edited the _PSS part of the tables adding 3 speedstep states for my CPU (I believe my CPU supports up to 8 states but this was a good start).

I was very lucky as there is already p-state example for my CPU (Q9450) on the net but this is also a very good guide to calculate FiD and Vid values for _PSS tables. Can be found here .

 

This gave some errors on compile but google gave me the answer, I had to change all Local0 entries. Very easy with 'find and replace' !

 

Add dropSSDT=y as boot argument and change acpi_smc_platformplugin plist to MacPro3,1 - or whatever Mac model you used the _cst tables from.

 

No need for disabler or voodoopower. This will give vanilla stepping and remove any _cst evaluation errors at boot.

 

Here is my dsdt09_08_09.dsl.zip For referance.

 

I do still have a slightly hight CPU temp but its far from off the scale (aprox 37C at 2.5GHz (75%) and 1.1V)

 

Also I have deep sleep with the one problem that my monitor does not wake - but I belive this is a problem with my ATI GFX and would be really interested to see if this method gives sleep to users who have lost sleep since 10.5.8.

 

Again YES this is a very basic guide. I'm happy to answer any questions and/or elaborate if asked.

If this appears to become popular I will find some time to tart up a better guide.

 

D.

[westwaerts]

thx for elaborating and collecting all this useful info.

 

for my understanding:

what for is the boot argument "dropSSDT=y" ?

 

i thought linux kernels cannot read any SSDT information out of the BIOS.

Thats we have to add it to DSDT.

 

sidefield: How many speedsteps you have added finally ?