get more vcore under load: vdroop pencil mod (pics)

[graysky]

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.

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!

 

[graysky]

What is your vdroop. There are really two of them:

1) Difference between BIOS and idle
2) Difference between load and idle

...I assume you googled around for the answer?

 

[Nitro350Z]

I Think I'll try this mod on my P5B (vanilla), I believe I found the correct surface mount component, will triple check it before I do the mod.

Just wondering, what happens if do the mod on the wrong surface component? Also, has anyone done this to the regular P5B, looked in a few places and all mention the P5B-Del but any question about the regular P5B go unanswered.

Will post results after I've done the mod.

 

[graysky]

@nitro - no idea about shading the wrong SMC. I would say good advice would be to undo the mod if you do boot into the o/s and find that your vdroop is still present and if you suspect you did the wrong SMC.

 

[Nitro350Z]

Alright, I've done the mod (at least tried...) and here were my results.

CPU Z was used for reading volts (know its not the best, but cant remember what program was better), used two instances of Prime95 (with affinity set correctly) for stress testing (max heat setting)

Before:
Idle: 1.352
Load: 1.296
Difference: 0.056

After (1rst try):
Idle: 1.352
Load: 1.312
Difference: 0.040

After (2nd try):
Idle: 1.352
Load: 1.320
Difference: 0.032

Between the first and second tries, I penciled over my first try adding another layer to the mod. Should I try a third time by doing it again? and I'm assuming I did it on the right component seeing as the Vdrop is less each time I added, is that right?

System is
C2D E4400 @ 3.0ghz (9x 333)
P5B Regular
2gb Crucial ram
HD2600pro
460W Tisonic PSU

 

[Nitro350Z]

Tried it a third time, and now I'm getting a Vdrop of only 0.008V
WooHoo! It works!

I'll post a pic of my mod for those interested in doing this on the P5B Vanilla.

 

[graysky]

Glad to hear it worked for you... I'm assuming your shaded the same SMC in my pic?

 

[Nitro350Z]

I believe it was the same one, had to orientate myself by looking at the markings on the SMC's from your pic, The mod worked so I think I picked the right one.

Here are the pics for the P5B regular.

Orientation shot

Close up showing which SMC it is.

And that's that.

HTH.

 

[graysky]

@Nitro - Here is a comparison pic of the deluxe to the vanilla

So if you start numbering the vertical SMC 1 through 6 (starting at the top and working your way down), on mine, #2 is the one to shade... looks like you shaded #1 on your board.

Well, you can't argue with results.

 

[Nitro350Z]

What you're saying is correct, but (unfortunately I couldn't get a better pic) the SMC that is labeled "010" is rotated 90* and sits above the one I shaded. The right column of SMC's beside the correct one seems to be shifted up in the regular P5B (also slightly reorganized). Thus causing confusion when trying the compare the deluxe to the regular.

I really wish that I could have taken a better pic...

Since the mod works, I either chose the right SMC by the above method, or I got really lucky with my pick.

 

[graysky]

How the hell could you read the writing on the thing? Maybe if I had a macro lens and tripod...

I'd encourage you to post a new thread for P5B Vanilla owners advertising this mod w/ you pics. In the text, write something like you did about (i.e. the #1 SMC is rotated 90 degrees, this is the right one to shade, etc.) You also might wanna post your before/after voltages. I'm sure there are lots of P5B Vanilla owners out there who would be very grateful.

 

[Nitro350Z]

Will do that, Will try and get a better pic too.

might as well also post results here.
(1.350v In Bios)Before: 0.056 Vdrop.
Idle: 1.352 Load: 1.296

(1.300v in Bios)After: 0.008 Vdrop
Idle: 1.296 Load: 1.288

HTH

 

[cheeseds]

I have vdroop on my EVGA motherboard (EVGA 122-CK-NF63-TR)

C2D E6600 set at 1.350v
no load - 1.320v
1 core loaded - 1.304v
both cores loaded - 1.296v
Total - .054v

I hesitate to start drawing on my motherboard because the if i get something wrong....so any help would be nice

 

[drysocks]

What are you actually doing by putting graphite on the ?resistor. Trimming the value lower? What is the function of that resistor? Any chance that it's a capacitor or inductor?

And the stumper to me. How did you find it and figure it out?

 

[Mugz]

He probably googled & downloaded the datasheet for that big chip next to the resistor, found it's feedback pin, then did some delicate work with a multimeter. That's usually the way to do it.

What the graphite does is provide a path for a very small amount of current to flow, which is added to the current going through the resistor itself - you're basically trimming resistance.

It may be a capacitor, but then something would've emitted smoke after the pencil mod. As for an inductor, well, inductors just don't come in that small.

 

[dobby]

this seem really odd to me, how does this work any one,

all i can think of is that the graffite will lower the resistance by letting some of the current bypass it?

 

[Chememan]

If the pencil mod works, what about the solder mod?

Maybe too much of a good thing?