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SSDT for E6520 with i7 2620M


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Hey, so I got speedstep working properly on my E6520 tonight, thought I would share my SSDT and how I created it. In another thread I stated that I had speedstep working...I was wrong :) NOW I have it working properly.


Here is how I generated a proper SSDT.aml:

  • Downloaded the ssdtPRGen.sh script from RevoGirl's blog here http://revogirl.wordpress.com/2012/06/16/bash-script-to-generate-ssdt-pr-dsl/
  • Modify the script (it wasn't generating data correctly since I think it was meant mainly for desktop processors and the data from sysctl wasn't quite right)
    • Search for all references to 1500. This is the min frequency it will generate steps for. You will need to figure out what the min frequency is for your CPU. I booted into Ubuntu and ran
      sudo cat /sys/devices/system/cpu/*/cpufreq/cpuinfo_min_freq

      which came up with 800000000 or 800 MHz, so I replaced all instances of 1500 with 800

    • In the main function on line 266 change the text that looks like
      let frequency=$(echo `sysctl hw.cpufrequency` | sed -e 's/^hw.cpufrequency: //')

      to just be

      let frequency=2700000000

      This is for the regular (non Turbo) clock speed. To figure this out I just had a quick look at the Intel product page here http://ark.intel.com/products/52231 and looked at the clock speed. Use an appropriate value for your CPU if different.


    sudo ./ssdtPRGen.sh 35 3400

    where 35 is the Max TDP which can be found on the Intel product page and 3400 is the max turbo frequency, also found on the product page.

    [*]This generates a file in /tmp/ssdt-pr.dsl, open it up in DSDT Editor, compile, save, and copy to /Extra/SSDT.aml


To verify it was working I found the MSRDumper.kext and ran

sudo kextload MSRDumper.kext

(you don't want to install this permanently, it gets annoying in the kernel.log)


I then ran geek bench and the kernel.log then showed:


kernel[0]: MSRDumper CoreMulti(9) 
kernel[0]: MSRDumper PStatesReached: 8 9 10 11 12 13 26 27 28 29 30 32


Hope that helps someone else. I am attaching my SSDT.aml I am using.




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What do you mean "post your CPU"? It's a i7 2620M (as stated in the topic title :)), is that what you are looking for?


Hello bpedman,


Can you please share your DSDT along with extra folder, I am trying to get my ML booting properly without any success, only option to boot in safe mode with no trackpad support. Or if possible help patch my Vanilla DSDT, which I am attaching.




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I'm getting this:


root@halo:~# ./ssdtPRGen.sh 17 3500

./ssdtPRGen.sh: 17: ./ssdtPRGen.sh: Syntax error: "(" unexpected


What linux distro did you use ?


Looks like the shebang is pointing to /bin/sh but it actually needs to be run using bash. Should probably update the script for that and/or run the script using bash directly, i.e.:

bash ssdtPRGen.sh 17 3500

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