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Today I was trying to hit 5ghz with my celeron on a gigabyte GA-EP35C-DS3R motherboard, but was getting EXTREME vdroop, which was limiting me quite a bit. The problem is that the voltage settings jump from 1,6 to 1.8v and nothing in between. I really dont want to fry this chip with 1.8v and with the horrible vdroop, I could only get 1.52v if I set 1.6v in the BIOS.

If anyone has a mod (be it pencil or a hard mod) please post here so I can hit 5Ghz tomorrow. (hopefully)

thanks
 

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http://www.madshrimps.be/vbulletin/f...isl6327-35371/
http://www.xtremesystems.org/forums/...d.php?t=162875
http://www.xtremesystems.org/forums/...d.php?t=147781

In the first link people worked together to discover the vcore mod. They were close to finding the vdroop mod. In the second link the guy took a punt at applying a vdroop mod and it seems to work. Third one is some additional interesting info.

In conclusion:
Vcore - connect 50k vr to ground from the red dot
Vdroop - we don't know the exact resistance to use but try connecting a 50k ohm VR/POt between points 1 and 6, set it to 20k, and slowly lower it until the vdroop is almost eliminated (don't completely eliminate it otherwise you will get instability issues). If someone could find the exact value that would be great
 

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Post some pics of the IC around your CPU. Most likely between your CPU and DIMMS.

EDIT: Looks like Tater Tot ninja'd in while I was typing.
 

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yeah tater tot I forgot to mention that its Rev 2.1 and the chips are different. Will take some pics now.

update in like 5mins or so
 

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Quote:

Originally Posted by wumpus View Post
yeah tater tot I forgot to mention that its Rev 2.1 and the chips are different. Will take some pics now.

update in like 5mins or so
NOOOOOOOOOOEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!! !!

So much wasted link grabbing.

Good thing I did have a folder in my bookmarks of P35C-DS3R vmods though.
 

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ok here is the pic. I tried to circle in red where I did an attemted penil mod that LOWERED the voltage and increased vdroop.

 

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ISL6327

Pin 16.

Test to see which point in the box is connected to the pin marked.
LL
 

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Quote:
Test to see which point in the box is connected to the pin marked.
lol im sort of a noob at this. What do I measure there?
resistance, volts?

thanks for all the help BTW!
 

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Most DMMs have a continuity test selection. When set to this selection it should beep when you have a connection.
LL
 

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ok i know its been a long time but i finally got around to measuring the points.

it seems that the middle one is connected to pin 16.

 

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Discussion Starter #11
how much resistance do i need between those points?
 

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nvm i figured this out.....

thanks for the help guys!

dont forget to put this in the volt mod thread

EDIT: pic was a failiure
 

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What did you do, shade the resistor?
 

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double post. occurrs when i use the back button to go to this page
 

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Discussion Starter #16
one of the links says to connect pins 15 and 17 together with a 100k VR and turn it down until no vdroop.....im not sure about it though as i cant find any evidence to support it...

resisitence between those points is supposed to be like 2.27k ohms or something....

 

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triple post
 

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quad post
 

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Ok, so it looks like you can attack this from two angles. I'm glad I reread the datasheet.

Datasheet for reference.




So there is IDROOP which I was looking at earlier.

Quote:
IDROOP - IDROOP is the output pin of the sensed average
channel current, which is proportional to the load current. In
the application, which does not require loadline, leave this
pin open.
In the application which requires load line, connect
this pin to FB so that the sensed average current will flow
through the resistor between FB and VDIFF to create a
voltage drop, which is proportional to the load current.
You can disconnect IDROOP(remove the resistor we labeled) to not use load line(vdroop).

Then there is the FB/VDIFF mod which you found.

Quote:
FB and COMP - The inverting input and the output of the
error amplifier respectively. FB can be connected to VDIFF
through a resistor. A properly chosen resistor between
VDIFF and FB can set the load line (droop)
, when IDROOP
pin is tied to FB pin. The droop scale factor is set by the ratio
of the ISEN resistors and the inductor DCR or the dedicated
current sense resistor. COMP is tied back to FB through an
external R-C network to compensate the regulator.
Here it tells us a VR somewhere between FB and VDIFF will set LLC, be careful not to have the VR between ground and FB or you'll get e vCore mod.


I'm leaning towards removing IDROOP as the mod to eliminate vdroop.
 

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Quote:

Originally Posted by PizzaMan View Post
Ok, so it looks like you can attack this from two angles. I'm glad I reread the datasheet.

Datasheet for reference.




So there is IDROOP which I was looking at earlier.

You can disconnect IDROOP(remove the resistor we labeled) to not use load line(vdroop).

Then there is the FB/VDIFF mod which you found.

Here it tells us a VR somewhere between FB and VDIFF will set LLC, be careful not to have the VR between ground and FB or you'll get e vCore mod.


I'm leaning towards removing IDROOP as the mod to eliminate vdroop.
ok I know its been a while its just been on the back burner.
Also, I think we found it out.

here is my paint diagram:



Quote:
A properly chosen resistor between
VDIFF and FB can set the load line (droop), when IDROOP
pin is tied to FB pin.
does that mean I solder all 3 together and put a 50k ohm resistor in between vdiff and FB? (resistance to ground was ~40K ohm for vdiff and FB)

Also, does the Idroop mod where I take out the resistor completely eliminate vdroop?

thanks for all your help man we are really close now
 
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