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Hacking Speedstep

K

kensenjiha

macrumors newbie
Original poster
May 25, 2010
18
0
Some terrible place
Older MacBook/MBP/MBA's run very hot. I'm trying to underclock them. already figure out a hardware method (https://forums.macrumors.com/showthread.php?p=13279309#post13279309). Reduced the FSB from 200MHz to 100/133/166MHz. Now i'm trying to undervoltage. It's not so practical hard way.

look into /S/L/Ex, there is a IOPlatformPluginFamily.kext/Contents/PlugIns/ACPI_SMC_PlatformPlugin.kext/Contents/Resources, some plist like "MacBookPro5_1.plist" seems contain speedstep policy inside. I did mod the GPU part. This can reduce GPU heating and loss some performance.

Code: 
<key>GPUThresholdDict</key>
<dict>
        <key>MacBookPro3,1</key>
        <string>TA2</string>
        <key>TA2</key>
        <array>
                <dict>
                        <key>high-threshold</key>
                        <integer>90</integer>
                        <key>low-threshold</key>
                        <integer>0</integer>
                        <key>threshold-method</key>
                        <integer>1</integer>
                </dict>
                <dict>
                        <key>high-threshold</key>
                        <integer>93</integer>
                        <key>low-threshold</key>
                        <integer>91</integer>
                </dict>
                <dict>
                        <key>high-threshold</key>
                        <integer>96</integer>
                        <key>low-threshold</key>
                        <integer>94</integer>
                </dict>
                <dict>
                        <key>high-threshold</key>
                        <integer>100</integer>
                        <key>history-length</key>
                        <integer>1</integer>
                        <key>low-threshold</key>
                        <integer>97</integer>
                </dict>
        </array>
</dict>


Now, I'm trying to hack StepDataDict under CtrlLoopArray, IE
Code: 
<key>MacBookPro3,1</key>
<string>SP1</string>
<key>SP1</key>
<data>xgYAAAAAAQIEAAACAgAAVQBuAHMAcABlAGMAaQBmAGkAZQBkDAAH/....(this binary value can be decoded by xcode or other plist tool)

Can any one help me to parse the structure of this binary data? I already found a unicode string "Unspecified", and 2 table like structure. one of them has 10 bytes in group,
Code: 
03 ff 00 0b 0f 00 00 ff 01 00
the other looks not very alligned, with "05 ff" pattern. 14 or 28 bytes in group.

here is whole data of MacBookPro3_1.plist
Code: 
c6 06 00 00 00 00 01 02 04 00 00 02 02 00 00 55 00 6e 00 73 00 70 00 65 00 63 00 69 00 66 00 69 00 65 00 64 0c 00 07 ff 07 00 00 21 00 00 00 02 00 00 01 ff ff 00 ff 00 ff 00 ff 00 ff 00 ff 00 06 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0f 00 00 ff 01 00 03 ff 00 0b 0a 00 00 01 0a 00 00 01 00 00 00 01 00 00 00 f5 00 01 05 00 00 01 00 00 05 ff 00 01 00 00 00 01 00 00 00 01 06 00 00 02 00 00 00 04 01 00 00 80 00 c3 00 b7 00 2e 00 34 00 0b 00 00 00 02 00 00 00 01 00 00 00 01 00 00 00 02 00 00 00 02 02 00 00 02 06 00 00 01 00 00 00 01 00 00 00 f5 00 01 05 00 00 03 00 00 05 ff 00 03 02 00 00 03 06 00 00 09 00 00 00 04 00 00 00 4c 00 04 05 00 00 04 00 00 05 ff 00 03 00 00 00 01 00 00 00 04 04 00 00 80 00 00 00 0a 0a 00 00 08 00 00 00 05 00 00 00 08 00 00 00 05 00 00 00 03 00 00 00 02 00 00 00 05 06 00 00 07 00 00 00 01 00 00 00 f5 00 01 05 00 00 06 00 00 05 ff 00 03 00 00 00 03 00 00 00 06 06 00 00 02 00 00 00 04 00 00 00 a0 00 0f 05 00 00 07 04 00 00 07 00 00 00 03 00 00 00 04 00 00 00 07 06 00 00 08 0a 00 00 03 00 00 05 ff 00 04 02 00 00 08 06 00 00 01 00 00 00 01 00 00 00 e8 00 03 05 00 00 09 00 00 05 ff 00 05 02 00 00 09 06 00 00 02 00 00 00 04 00 00 00 e8 00 03 05 00 00 0d 00 00 00 0a 00 00 00 0d 00 00 00 0a 00 00 00 05 00 00 00 01 00 00 00 0a 06 00 00 07 00 00 00 01 00 00 00 f5 00 01 05 00 00 0b 00 00 05 ff 00 05 00 00 00 02 00 00 00 0b 06 00 00 02 00 00 00 04 00 00 00 a0 00 0f 05 00 00 0c 04 00 00 0c 00 00 00 05 00 00 00 03 00 00 00 0c 06 00 00 08 0a 00 00 09 00 00 05 ff 00 06 02 00 00 0d 06 00 00 01 00 00 00 01 00 00 00 e8 00 03 05 00 00 0e 00 00 05 ff 00 07 02 00 00 0e 06 00 00 02 00 00 00 04 00 00 00 58 00 1b 05 00 00 12 00 00 00 0f 00 00 00 12 00 00 00 0f 00 00 00 07 00 00 00 01 00 00 00 0f 06 00 00 07 00 00 00 01 00 00 00 f5 00 01 05 00 00 10 00 00 05 ff 00 07 00 00 00 02 00 00 00 10 06 00 00 02 00 00 00 04 00 00 00 a0 00 0f 05 00 00 11 04 00 00 11 00 00 00 07 00 00 00 03 00 00 00 11 06 00 00 08 0a 00 00 0e 00 00 05 ff 00 08 02 00 00 12 06 00 00 01 00 00 00 01 00 00 00 e8 00 03 05 00 00 13 00 00 05 ff 00 09 02 00 00 13 06 00 00 02 00 00 00 04 00 00 00 fc 00 08 05 00 00 17 00 00 00 14 00 00 00 17 00 00 00 14 00 00 00 09 00 00 00 01 00 00 00 14 06 00 00 07 00 00 00 01 00 00 00 f5 00 01 05 00 00 15 00 00 05 ff 00 09 00 00 00 02 00 00 00 15 06 00 00 02 00 00 00 04 00 00 00 a0 00 0f 05 00 00 16 04 00 00 16 00 00 00 09 00 00 00 03 00 00 00 16 06 00 00 08 0a 00 00 13 00 00 05 ff 00 0a 02 00 00 17 06 00 00 01 00 00 00 01 00 00 00 e8 00 03 05 00 00 18 00 00 05 ff 00 0b 02 00 00 18 06 00 00 02 00 00 00 04 00 00 00 28 00 0a 05 00 00 1c 00 00 00 19 00 00 00 1c 00 00 00 19 00 00 00 0b 00 00 00 01 00 00 00 19 06 00 00 07 00 00 00 01 00 00 00 f5 00 01 05 00 00 1a 00 00 05 ff 00 0b 00 00 00 02 00 00 00 1a 06 00 00 02 00 00 00 04 00 00 00 a0 00 0f 05 00 00 1b 04 00 00 1b 00 00 00 0b 00 00 00 03 00 00 00 1b 06 00 00 08 0a 00 00 18 00 00 05 ff 00 0c 02 00 00 1c 06 00 00 01 00 00 00 01 00 00 00 f4 00 01 05 00 00 1d 00 00 05 ff 00 0d 02 00 00 1d 06 00 00 02 00 00 00 04 01 00 00 80 00 c3 00 b7 00 2e 00 34 00 0b 00 00 00 1d 00 00 00 1e 00 00 00 1d 00 00 00 1e 00 00 00 0d 00 00 00 01 00 00 00 1e 06 00 00 07 00 00 00 01 00 00 00 f5 00 01 05 00 00 1f 00 00 05 ff 00 0d 00 00 00 02 00 00 00 1f 06 00 00 02 00 00 00 04 00 00 00 a0 00 0f 05 00 00 20 04 00 00 20 00 00 00 0d 00 00 00 03 00 00 00 20 06 00 00 08 0a 00 00 1d 00 00 05ff

maybe we can hack these to change CPU/GPU Frequency / Voltage settings.
 
kensenjiha said:
Older MacBook/MBP/MBA's run very hot. I'm trying to underclock them. already figure out a hardware method (https://forums.macrumors.com/showthread.php?p=13279309#post13279309). Reduced the FSB from 200MHz to 100/133/166MHz. Now i'm trying to undervoltage. It's not so practical hard way.

look into /S/L/Ex, there is a IOPlatformPluginFamily.kext/Contents/PlugIns/ACPI_SMC_PlatformPlugin.kext/Contents/Resources, some plist like "MacBookPro5_1.plist" seems contain speedstep policy inside. I did mod the GPU part. This can reduce GPU heating and loss some performance.

maybe we can hack these to change CPU/GPU Frequency / Voltage settings.
Click to expand...


Very cool. Did you ever get any success with this?
 
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