get more vcore under load: vdroop pencil mod for p5b-deluxe

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graysky
Posts: 147
Joined: Fri Sep 16, 2005 4:14 pm
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get more vcore under load: vdroop pencil mod for p5b-deluxe

Post by graysky » Fri Jul 20, 2007 12:03 am

This is one of the easiest mods you can do to your P5B-Deluxe (and probably any P5B although I haven't tested it on any model but the Deluxe) to help you get higher voltages under load conditions and also lower your idle vcore; it is particularly useful for people wanting to get more juice to feed their o/c'ed chip.

Background
As you know, the P5B-Deluxe (and others in the P5B family) has a vdroop built in for some reason (protect processor maybe, I dunno). Vdroop is the term used to describe the voltage drop between idle and load conditions.

Try it yourself right now: (assuming you have your vcore manually set in your BIOS) load up CPU-Z and see what it's reporting as your idle vcore. Now load up a few instances of orthos and have a look. For example, before the mod, mine dropped from 1.280v (idle) to 1.232v (load) which is -0.048v! After you do the "pencil mod" it should drop by a very small amount or none.

The "Pencil" Mod

What do you need? A soft pencil. Look for one with a 2B rating on it. Standard pencils are HB. HB pencils will work, but the softer the pencil lead, the better the results. You can find a 2B pencil at most any office supply store (staples, officemax, etc.); they are usually in the art or drafting section (aisle #7 for my staples). I got one in 4 pack for under $3.

Now, either unplug or switch off your power supply so the LED has gone out and simply shade (gently draw with the pencil back and forth) over the correct surface mount component (it's a resistor maybe?) -- refer to the pictures below... it's the one with the yellow arrow pointing to it.

Image
Image
You can see on the zoom where I colored over the right one.

NOW, boot into Windows and repeat that exercise where you measure the load and idle vcore. Mine went from a drop of 0.048v before I did the mod to a drop of 0.008v after the mod. These are both @ a BIOS vcore of 1.3250v.

I recently lowered the BIOS vcore to 1.2625v and now I have NO vdroop at all: idle is 1.232v and load is 1.232v, and the system is stable to 2x orthos for over 6 h!

Undoing the "Pencil" Mod

You can undo this very easily with a little alcohol and a few q-tips. It is 100 % reversible.

If you found this useful, please post your before/after results in this thread.

Enjoy!

jojo4u
Posts: 806
Joined: Sat Dec 14, 2002 7:00 am
Location: Germany

Post by jojo4u » Fri Jul 20, 2007 1:22 am

Why won't you just activate C1E?

davexl
Posts: 14
Joined: Tue Dec 06, 2005 11:51 pm

Post by davexl » Fri Jul 20, 2007 5:07 am

jojo4u wrote:Why won't you just activate C1E?
Becuase that won't always work when overclocked.

THis pencil mod is awesome, I did it a few weeks back and saved 20w at idle on a quadcore...

http://www.xtremesystems.org/forums/sho ... tcount=222

to the OP - spread the word :wink:

graysky
Posts: 147
Joined: Fri Sep 16, 2005 4:14 pm
Location: My desk

Post by graysky » Fri Jul 20, 2007 10:25 am

davexl wrote:
jojo4u wrote:Why won't you just activate C1E?
Becuase that won't always work when overclocked.
Not true. I have all the power saving options (i.e. speedstep, C1E, etc.) enabled on my Q6600/P5B-Del machine and they work just fine@ 9x333.

cmthomson
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Joined: Sun Oct 09, 2005 8:35 am
Location: Pleasanton, CA

Post by cmthomson » Fri Jul 20, 2007 6:39 pm

I know this is about the P5B...

On a P5W DH MB, you must disable EIST, C1E, etc, etc, to successfully overclock. The pencil mod on this board is the only reliable way to get rid of Vdroop, unless you simply choose to ignore it, as I did.

davexl
Posts: 14
Joined: Tue Dec 06, 2005 11:51 pm

Post by davexl » Sat Jul 21, 2007 12:23 am

graysky wrote:
davexl wrote:
jojo4u wrote:Why won't you just activate C1E?
Becuase that won't always work when overclocked.
Not true. I have all the power saving options (i.e. speedstep, C1E, etc.) enabled on my Q6600/P5B-Del machine and they work just fine@ 9x333.
Not not true; true! 8)

Sorry, that is hardly overclocked in my book. Try it at 9x390 = 3500Mhz Boom.

This pencil mod is awesome.

jojo4u
Posts: 806
Joined: Sat Dec 14, 2002 7:00 am
Location: Germany

Post by jojo4u » Sat Jul 21, 2007 11:25 pm

Ok, so C1E does not work. What about tailoring your own RMClock profile? The background why I don't like the droop reduction is that intel is not stuped. The droop sould be tailored around the properties of the CPU so that you don't loose stability when comparing light load vs high load. Reducing the droop could just give you higher stability under heavy load/high temperature but less under light load/low temperature compared to a setup where the light load vcore is higher.

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