Jump to content

CPU Powermanagement on Core i5-760


Recommended Posts

Hi. Since getting CPU power management working on my Acer v5-171, i went back to the desktop that's been running Mountain Lion since day 1.


At boot and in about this mac, cpu is reported as i5 running at 2.93 GHz. Installed new FakeSMC and HWmonitor because I always thought the machine could be a bit sluggish. Suspicions are confirmed by the cpu frequencies.


I was using Generate P states and C states in org.chameleon.boot.plist but HW monitor shows two states - 1.2GHz idle and 2.13 GHz at load. Doesn't matter how many things I run it never goes above 2.13 GHz. Intel specs show the i5-760 should have turbo of 3.33 GHz. I'm using chameleon wizard iMac 11,3 smbios.plist which matched my i5-760 CPU and ati video card.


I tried using ssdtPRGen and put in max frequency as 3330 and TDP of 95w (from the intel specs). It generated a bunch of states but when I drop this into /Extra and modify org.chameleon.boot.plist accordingly (to remove the generation of P and C states and Drop SSDT) HWMonitor still gives me the same readings.


iMac:Desktop mark$ ./ssdtPRGen.command 3330 95



sdtPRGen.sh v6.6 Copyright © 2013 by Pike R. Alpha


Warning: Unexpected brandstring > "Intel® Core i5 CPU 760 @ 2.80GHz"

Processor Declaration(s) Found in DSDT (ACPI 1.0 compliant)

Generating ssdt_pr.dsl for a iMac11,1 [Mac-F2268DAE]

Unknown Core i5 processor [0x106E5] setup [0x0601]

Override value: Max Turbo Frequency, now using: 3330 MHz!

Override value: Max TDP, now using: 95 Watt!

Number logical CPU's: 4 (Core Frequency: 2933 MHz)

Number of Turbo States: 3 (3033-3330 MHz)

Number of P-States: 18 (1600-3330 MHz)

./ssdtPRGen.command: line 635: [: -eq: unary operator expected

./ssdtPRGen.command: line 706: [: -eq: unary operator expected

./ssdtPRGen.command: line 2068: [: -eq: unary operator expected

./ssdtPRGen.command: line 1022: [: -eq: unary operator expected

./ssdtPRGen.command: line 1044: [: -ge: unary operator expected

./ssdtPRGen.command: line 1044: [: -ge: unary operator expected

./ssdtPRGen.command: line 1044: [: -ge: unary operator expected

Injected C-States for CPU0 (C1,C3,C6)

./ssdtPRGen.command: line 1457: [: -ge: unary operator expected

./ssdtPRGen.command: line 2092: [: -ne: unary operator expected


Intel ACPI Component Architecture

ASL Optimizing Compiler version 20130117-64 [Jan 19 2013]

Copyright © 2000 - 2013 Intel Corporation


ASL Input: /Volumes/Data/Users/mark/Desktop/ssdt_pr.dsl - 154 lines, 4494 bytes, 29 keywords

AML Output: /Volumes/Data/Users/mark/Desktop/ssdt_pr.aml - 942 bytes, 11 named objects, 18 executable opcodes


Compilation complete. 0 Errors, 0 Warnings, 0 Remarks, 0 Optimizations


Is this something to do with the DSDT i originally used from TM?



I've attached it here incase anyone can see this issue.


Thanks, sem



Link to comment
Share on other sites

Weird - I installed latest Chameleon instead of chimera (chameleon, stolen and rebranded), tried regenerating SSDT etc.  reset the motherboard bios to defaults - no difference.  Multiplier goes from x9 to x16 max yet About this Mac shows i5 at 2.93 GHz.


Then, I dropped the SSDT from /Extra, changed org.chameleon.boot.plist to Generate P and C states and removed the DropSSDT key.  Rebooted.  About this Mac showed i5 @ 2.80 GHz then HWMonitor shows CPU idle at 1.2GHz (x9 multiplier) jumping to 2.93 GHz (22 multiplier) Only two states but it idles with no load at 1.2 GHz - i can also see the voltage changing from 0.93v to 1.02v under load.


Does this sound about right? For a non sandy bridge CPU would CHameleon only generate  two SpeedStepping states?  Is this something that a patched AppleItelCPUPowermanagement kext would fix?


thanks, sem

Link to comment
Share on other sites

Another update - changed to Mac Pro 3,1 smbios from CHameleon Wizard, rebooted, About This Mac still shows i5 @ 2.8 GHz but now HWmonitor shows cpu cycling with multipliers ranging from 9, 10, 11, 12, 13 and finally 22.


So the CPU frequency appears to be stepping - however, I thought that self and auto generated P and C states would be 1600 for a Desktop cpu and going down to 1200 for a mobile CPU only?



Link to comment
Share on other sites

  • Administrators

We've posted an article about this in the "Articles" section of the Web site. You would need to find the Mac that best matches your own specs, then edit Fake SMC to include the associated SMC key id.

Link to comment
Share on other sites

Brilliant!  Thanks for that.  I did read somewhere by the guy that did HDAEnabler that iMac's tend to have two power states - idle and full - that would explain why when using iMac 13,1 we go from 1.2 GHz up to 2.96 GHz.  


One question though when matching specs, doing so with an iMac would be tricky anyway, right because they use many mobile parts?  For example, I've got a Gigabyte GA-H55M-UD2H board, i5-760 cpu and currently run an ATI 5570 VGA card.  So looking at EveryMac.com, the iMac 13,1 or the MacPro 5,1 seem closest specwise - but what would you prioritise when assessing how close the specs are?


thanks again, sem.

Link to comment
Share on other sites

  • Create New...