i7 860 Over-clocking

[Bansaku]

@IceBear
That's exactly what I wanted to know (DSDT info needed for OC). I too have had (the same) OC stability issues without knowing what the problem might be. The first part of the puzzle is solved at least. Now we just gotta figure out why? Myself, I would assume that SS info in the DSDT would somehow counteract OC yet it is needed for stability eh? And at the same time if you want native SS/Turbo values (I find) the DSDT doesn't like it when you edit it. Very odd.

 

[madguy]

Today is a great day for me. After so many days/nights and loosing few hairs, I stumble on ibruno post http://www.tonymacx86.com/viewtopic.php?f=14&t=571&start=10

Also, every time that I have removed the NullCPUPowerManagement.kext from my system, my GeekBench 64 score has dropped from 9500 to 3900! Replacing the NullCPUPowerManagement.kext brings it back up to 9500, but any ideas why removing this kext would cause such a drastic drop in my Geekbench 64 score? I thought this kext was not even needed?

So here are some charts:

SL 10.6.2 side:

Default, CPU 2.8 GHz, memory 1333 MHZ
no NullCPUPowerManagement.kext, DSDT from here

====================
CPU 3.36 GHz, memory 1600 MHZ :
no NullCPUPowerManagement.kext, DSDT from here

====================
CPU 3.36 GHz, memory 1600 MHZ
NullCPUPowerManagement.kext IN E/E AND DSDT from here

istat at idle 31c
====================
====================
WIN 7 ultimate 64 Side

Default, CPU 2.8 GHz, memory 1333 MHZ

====================
CPU 3.36 GHz, memory 1600 MHZ

real temp 31c /prime95 8 test max temp 51c

So the key for ME is to have NullCPUPowerManagement.kext in E/E
Does other OCers have NullCPU in E/E too?

 

[rich]

try setting EIST to enabled in the BIOS. i tried over clocking my Core i5 with a DSDT from the latest MultiBeast (enables Speedstep) and resulted in my CPU always running at the lowest stepping clock giving a low geekbench score.

setting to enabled allowed my CPU to run at full overclock resulting in a higher score. the cpu clock also steps back down when idle and turbo boost works. im not using NullCPUPowerManagement either.

 

[IceBear]

I'd recommend not just setting EIST to enabled but all the other settings as well. Don't leave them on Auto - the BIOS interprets Auto differently when you start to OC.

Just be aware that when you're overclocking you need to remember the Turbo will kick-in. Start conservatively then build up.

If you want to aim high immediately you are much better turning off EIST and Turbo so you know exactly what you are dealing with.

 

[IceBear]

@IceBear
That's exactly what I wanted to know (DSDT info needed for OC). I too have had (the same) OC stability issues without knowing what the problem might be. The first part of the puzzle is solved at least. Now we just gotta figure out why? Myself, I would assume that SS info in the DSDT would somehow counteract OC yet it is needed for stability eh? And at the same time if you want native SS/Turbo values (I find) the DSDT doesn't like it when you edit it. Very odd.

Cool, at least I'm not alone

My guess is that OSX is thinking I have a different CPU and might be applying different voltages than the chip likes. C2D voltages are very different to the i7. When we hard-code the speedstep into the DSDT we also set the stepping voltages.

What I don't get and can't guess at is why when the SpeedStep defines the highest step why the machine will jump past that to whatever you've OC'd to. Doesn't make much sense.

 

[rich]

I'd recommend not just setting EIST to enabled but all the other settings as well. Don't leave them on Auto - the BIOS interprets Auto differently when you start to OC.

Just be aware that when you're overclocking you need to remember the Turbo will kick-in. Start conservatively then build up.

If you want to aim high immediately you are much better turning off EIST and Turbo so you know exactly what you are dealing with.

turbo and speedstep worked perfectly for me with everything on auto at stock. now im just doing a little overclock to 3GHz, but will now set everything to enabled as per your advice thanks

atm turbo is getting up to 3.5GHz for single and dual threaded processes which is fine for me while still getting the normal thermal spec of 3GHz.

 

[madguy]

so I have enabled EIST and TURBO in the bios. Here are GeekBench 64 results

SL 10.6.2 no speedstep in DSDT yet

and on Window 7

notice how on Windows GeekBench report the processor is at 2.8 GHz

 

[Bansaku]

@Madguy
Those results are more typical. You are on the right path.

Just a friendly FYI, "Auto" does not mean "Enabled". I got the exact same score spread after I did my BIOS update and overlooked "Enabling" the advanced CPU features. Needless to say after a hour of troubleshooting and my patience wearing thin I felt pretty stupid when the solution came to me.

Just some food for thought; Unless you are OC for use with Windows, there really isn't too much of a real world performance gain for OS X. My findings OC to a stable 3.8GHz that I got 3fps increase on average in WoW, and I took off a mere 4 minutes from 1h 45m converting a movie in Handbrake (all cores throttle to 100% burn). Saw no gain in converting in iTunes or compressing files in Stuffit as well. GB64 OC was 14 000 and 10 500 without.

 

[Evildemon989]

Mostlikely, the problem with the score of 4400 or something low like that is because youi disabled speedstep in the bios.

 

[IceBear]

so I have enabled EIST and TURBO in the bios. Here are GeekBench 64 results

Good scores. I've got my 32-bit Geekbench score to 10,500 and I'm pretty happy with everything now. Idle is mid 30's and under full mprime load it will touch 75Deg.

Happy to post my settings if anybody is interested; just let me know.

I did go much higher but then backed it all out to stay within Intel's power specifications for the i7. Intel actually say you shouldn't run your chip at over 72DegC; but the local computer store that sells OC'd gaming rigs run their clients chips up to 90-95deg constantly without issues.