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Intel x7900 Free Multiplier and VoodooPState


tweakbsd

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Hey guys,

 

I just imagined upgrading my D630 to an x7900 Core 2 Duo Extreme @ 2.8Ghz.

The specs tell that this CPU has free multiplier, so I need some help in configuring VoodooPState Kext.

 

I know there is a way to tell VoodooPState which states are available through Info.plist. But I'm not able

to find a guide or how-to.

 

Someone here maybe knows how to do it.

The reason is I want to try to overclock the x7900 to 3Ghz. Under Windows it can be easily done through

RightMark CPU Utility. But since I hat Windows and even don't want it, no way to go with it ;-)

 

Thanks in advance.

 

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Well, I'd suggest to test this in Windows. Theoretically, X7xxx or X9xxx Extreme C2D CPUs could be supported by the D630, being FSB800 processors. As long as the BIOS does not reject them, there's no technical reason they would not work... They might just run hot (44W vs 35W on the "regular" C2D).

 

I think I remember reading on an overclocking forum that someone did indeed run an X9000 in a D630 and pushed it up to 3.7GHz by raising FSB to 1066MHz through PLL-mod! Impressive if it worked and was sustainable!

 

I, myself, am a bit unconvinced re: heat and cooling...

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I'm Aware that I go back to 65nm and have 44W TDP...at the Moment I Run a

T8300 @2.4 with Arctic Silver Thermal Grease at 45 degrees idle and max load at

65 which is near Perfect values and Lower is Almost impossible due to

The fact i have NVIDIA graphics...so Heat isn't a Problem!

 

I will do some Research on pll modding ;-) but

Voodoo pstate configuration is the Thing i Look for...

 

Please help I know it is Possible but dont have Time to

Dive into its Code...

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A smart trick it so verify with coolbook and use the coolbook-fix - coolbook uses another method of extracting p-states.

Also, what is important to understand is that p-states will take you alot of the way, but if you want to really cool down your machine you need to look into patching for c-states (voltage) aka SSDT

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That was also my thought that PStates take me into the right direction...But is CoolBook running at the moment on Lion or ML ? The fix ?

 

And Cooling Down isn't my intention, the CPU resists alot of heat, 90°C degrees without problem and I think I won't reach it with 3Ghz and my current cooling which is like a charm.

 

 

And the 3Ghz Multiplier will be reachable via the IDA (Dynamic Acceleration) Multiplier of the CPU, I'm sure. I have

made a lot of tests with RightMark CPU Utility in Windows on many Santa Rosa CPUs and almost all of them can be runtime-patched

to run with one (some only a half) multiplier higher. And that is what I want to do. Set multiplier to 15 and Voltage to max (1.375V)

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I think your keyword here is SSDT tabels :) .. i could be wrong.. but i'm pretty sure you need to get the voltage under control to get it right.

Exampel, i have the Samsung 900x3c .. it have a Core i5 1,7ghz, its a vpro cpu that can go up to 2,4ghz via turbo-boost, with ssdt tabels patched its now using the turbo boost as part of the normal p-state range.. meaning by machine is much faster in osx than in windows where there usually would be a delay before it activated TB

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Okay, did a little research on SSDT Tables...definetly another good direction which could be used to get PStates and Voltages !

Patching them is difficult...so I really had a look at VoodoPState source which is kind of messy code, but I can now manipulate PStates

and voltages at the moment by defining them in the Info.plist file, that is good enough for me since I manage to get the IDA

multiplier working for my current T8300 which can now run at 2.5Ghz permanently, don't know if both cores are at that speed but mostly they are.

 

So I go for the Extreme x7900 CPU on eBay...further details follow then :-D

 

P.S.: If anyone is interested in details on VoodooPState configuration let me know...in spare time I will help you out ! 

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@tweakbsd: sounds interesting.

 

I had looked at Intel's IDA in C2D datasheets in the past and it indicated that only 1 core could be boosted whilst the other was idle. I believe that  the same principle has been retained over to the i core generation, although I'm not 100% certain of it. To me, your T8400 forced@IDA frequency runs on single core only.

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