Undervolting Core Duo & Core 2 Duo by Pin Mod - PART 2

[naton]

UPDATED 20th MAY 2009

I successfully undervolted via pin mod the T5300 by 0.2v . Without pin mod, and using RMclock the T5300 runs stable with a vcore of 0.9500v for all its multipliers.

The pin mod consisted on connecting ViD4 to the closest Vcc to force it to be High (1) all the time. After the pin mod those are my readings:

------- RMclock -- real vcore
06x --- 0.9500v --- 0.7500v
07x --- 0.9500v --- 0.7500v
08x --- 0.9625v --- 0.7625v
09x --- 1.0000v --- 0.8000v
10x --- 1.0375v --- 0.8375v
11x --- 1.0750v --- 0.8750v
12x --- 1.1000v --- 0.9000v
13x --- 1.1250v --- 1.1250v

If you want to read more about my experiments download the following PDF

[kaltmond]

I pinmod the Q9200 from 1.1625V to 1.0375V, at least it didn´t die. And i think the mod is successful because temp really lower than before. Don´t know about lower multis, i alwasy use full speed.

How do you know your default Vcores x10 is 1.2615V? Read from CPUZ?

[naton]

How do you know your default Vcores x10 is 1.2615V? Read from CPUZ?

I read it from RMclock "CPU info" panel.

Kaltmond why did you do your undervolt? what did you connect to what?

[kaltmond]

I think RMclock read the same like CPUZ, but i think it´s not correct. Try use Core temp to get the default VID, that should be the real one.

Under full load 4 cores create too much heat there, so i need it to run cooler.
I connect from 0011011 to 0100101, VID1/3/4 to VSS, VID 0/2 to VCC, and a long wire to connect VID5 to VCC.......Totally 6 copper wires......

[naton]

6 wires that's impresive
thanks for the info regarding Core temp

[shenofjo]

i been looking online on pin modding.... and i find nothing... how do i unlock voltages... i am limited to min of .9 v on my t9400, and i am at .9v from 6x - 8x multiplier... im sure i can go lower.

[Commander Wolf]

I'm mildly interested in undervolting via pin mod (as a method to bypass Intel's blasted VID lock), but unfortunately there's not much I can contribute from my own knowledge. You might want to try contacting this guy, though; he seems to be pretty well read in the matter:

http://forum.notebookreview.com/show...39#post4659239

Also might want to try reading that RMClock forums thread if you haven't already; though some of the information might just be repetitive. It kind of just went over my head for the most part -_-

[naton]

Commander Wolf thanks for your comment.
I've read everthing I could find on the internet about this subject as I've looking into doing it for the past year. I also exchanged few PMs with heinz2005 regarding this subject.

1- Can someone explain what I did wrong to end up rizing the Vcore instead of decreasing it?
2- Any good software to read the Vcore before pin mod? or is RMclock reading accurate?

[heinz2005]

A concept for a dynamic undervolting may be to connect VID0 to VID5.
The result should be a mapping to a range of 0,9375 down to 0,7125.

[heinz2005]

Here is a small electrical diagram of a typical CMOS-Output circuit (simplified):

I think at the mobile processors Intel use CMOS-Output to minimize the power drain.
So a pinmod to VCC or VSS would be a shortcut of one of the driver transistors. :-(
So I have to be very careful with pinmodding the VIDs.

IMHO the VID-Output goes directly to the voltage regulator chip.

What is the relevant specification for the Montevina voltage regulation?
"IMVP-6+. (or Intel MVP-6+). Intel Mobile Voltage Positioning – revision 6+."

If we do any pinmod (without soldering) we should take care of the driver transistor e.g. by using maybe
a resistor pulling the VID softly to another binary value.
The resistor can be sized according to the inner resistance of the activated CMOS gates.


Source: http://www.xilinx.com/support/docume...es/xapp329.pdf