P5N-E vmods

[couppi]

I did a continuity check and all that. Resistance between pin 17 and pin 16 is 125-130 kohm. I don't know which one of the two points to use.



I also got 1.2 kohms between FB and ground. Does that sound right?

[zeeke]

Any updates on vdroop mod?

[VASkO]

the board's vdrop is baaaaad. 1.45V in bios, 1.43V actual, 1.37V under orthos load at only 3ghz with an e4300. I wonder what an OCed QuadCore would do to this poor power design.

Correct me if i'm wrong, but can't the board be upgraded to 4 phase design with soldering the MOSFETs, the coil, the IC with 8 legs and some smd components to the empty mounting points on the PCB right next to the NB? Seems to me, there will be a P5N-E+ version of the board with the same PCB but with 4-phase power design.

What about adding capacitors to every empty mount point for round capacitors. Maybe it would help with 1T overclocking stability. When doing this, is there something, to pay attention to (capacitance, voltage of the capacitor to use...)??? I would like to do that mod, maybe Hipro5 would have to say something about this idea.

-- atached pictures with the empty power regulation area on the mobo. doable?


empty area - you can see where the coil and the fets go, also the 8 leged IC and other smd parts


populated area

here we have the following SMD components representing one phase:
-3 power FETs
-1 coil
-2* 1R0 smd resistor with 1Ohm resistance each
-2* 822 smd resistor with 8.2kOhm resistance each
-1 4.3Ohm smd resistor
-4 smd capacitors of (at this time) unknown capacitance
-3110 IC
-fuse

perhaps i can get a hold of these and mount them, is the job done then?

would this work? or are there also limits within the mobo's BIOS, so adding components would cause nothing but troubles?

[dlxmax]

Any updates on the vdroop mod?

[celemine1Gig]

Any updates on the vdroop mod?

OK, I thought everything was clear, but I don't have much free time at hand ATM, so please just do the following:

Please double check the resistance between pin#16 and pin#17 according to this post from couppi:

http://www.xtremesystems.org/forums/...2&postcount=26


Now if the stated ~130K between these two pins are correct, then the info from the first pic also applies. That means you'd have to use at least a 1M trimmer potentiometer for this mod.

(130k x 1000k) / (130k + 1000k) = ~115k

115k / 130k = ~88.5%

That means a 1M resistor already decreases the original resistance by upto ~11.5%. That's a bit much for my liking, but as the droop seems to be so bad on that board, it could work very well without any harm.

Try it, as always on your own risk. You know that you have to adjust the potentiometer until the vcore at idle and at load are identical. Don't overdo it, thus vcore at load is higher than at idle! That wouldn't be good. If the 1M shouldn't be enough, just add another 500k trimmer in series to the 1M, for a total of 1.5M resistance. With the 1.5M the decrease in resistance compared to the original value would still be about 7.5%. But as I said, you'll have to try. I guess that the 1M trimmer will work fine.

The alternate solder points are already marked in couppi's pic. You could also double check these, but I doubt that he made a mistake there.

[couppi]

Thanks celemine1gig. I'm going to try this as soon as I get my hands on a soldering iron. Can someone please double check my measurements? I'm not sure that I got everything right.

[dlxmax]

Thanks for coming back, Celemine.

I'd be testing those spots right now--but I gave my multimeter away when I moved. Guess I have an excuse to buy a new one...

Couppi, a soldering iron is $5-$10 at Radio Shack. You don't need anything fancy, just get the one with the finest tip and the lowest wattage.

[zeeke]

Ok, this is a measurement of actual vdrop during load. 1.525V selected in bios. With the +100mV disabled

[Ron 61]

Thanks zeeke. What voltage is your bios reporting at those settings. When I select 1.4625 my bios reports 1.39, just curious to what difference you get with your board. Your meter reconfirms software voltage monitoring is next to useless.

[dlxmax]

Thanks zeeke. What voltage is your bios reporting at those settings.

He said above he selected 1.525v in the bios, which splits the difference between the load and idle voltages.

[celemine1Gig]

He said above he selected 1.525v in the bios, which splits the difference between the load and idle voltages.

Yeah your observation seems to be right.

Could very well be likely that ASUS intentionally adjusted the boards so that they give a little higher VCore in idle, thus the window for droop get's wider and they could safe even more money than when calculating from the voltage really selected in BIOS. Quite smart move when judged by a commercial point of view. For us enthusiasts it's the other way round unfortunately.

[Ron 61]

He said above he selected 1.525v in the bios, which splits the difference between the load and idle voltages.

Yes thats obvious, I asked what his bios was reporting.

[zeeke]

I'll check, in the middle of 3dmarkin now, but if i remember correctly its something like 1.36 during load. Dunno idle. It doesnt really matter since its way off..

[Ron 61]

What I am interested in is when you are in the bios what does hardware monitor report for vcore versus the vcore your meter shows. Thanks.

[zeeke]

What I am interested in is when you are in the bios what does hardware monitor report for vcore versus the vcore your meter shows. Thanks.

1.6V selected is reported as 1.53V in BIOS and is 1.58V measured @ IDLE

[Ron 61]

Thank you zeeke.

[inspector-71]

sorry for the noob question but I hope someone can help me

I need to get a bit more vcore out of this board to get stable at 4 gig
what can I expect from the pencil mod shown here?
http://www.vr-zone.com/?i=4450&s=12
Will it just mean I get more volts than I currently get when I set 1.6 vcore in the bios? how much increase can I expect?

Do you just scrub a line with a 2b pencil between the points shown ( first attempt at volt mods )?

[zeeke]

sorry for the noob question but I hope someone can help me

I need to get a bit more vcore out of this board to get stable at 4 gig
what can I expect from the pencil mod shown here?
http://www.vr-zone.com/?i=4450&s=12
Will it just mean I get more volts than I currently get when I set 1.6 vcore in the bios? how much increase can I expect?

Do you just scrub a line with a 2b pencil between the points shown ( first attempt at volt mods )?

First of all, get yourself a multimeter, its worth the small investment so you dont burn your cpu when you do the vmod. You have to be able to measure the voltage if you do a pencil mod, because there is now way to say just how much you will lower the resistance with each stroke. In that way, soldering a trimpot is safer, and more accurate.

[inspector-71]

First of all, get yourself a multimeter, its worth the small investment so you dont burn your cpu when you do the vmod. You have to be able to measure the voltage if you do a pencil mod, because there is now way to say just how much you will lower the resistance with each stroke. In that way, soldering a trimpot is safer, and more accurate.

i have one

So if I understand correctly after some reading

I should measure the default resistance with the motherboard disconnected from the power.
I know the current vcore from the bios or other measurement
I can calculate the current from ohm's law

then I pencil the resistor (using a 2b pencil)
measure the new resistance
calculate the expected vcore and if it's safe give it a go

[dlxmax]

Arrgh, in Celemine's post above (#30) he first says that you'd need to use a "1K" trimmer, then all references after that are to a "1M" trimmer. I know he initally meant to say "1M", but damnit I saw "1K" and that's what I bought at the store today. Of course I paused and stared at the "1M" for a couple of minutes and wondered if I was getting the right one. I should have bought both--but didn't. Guess where I'm going back later this week?

[celemine1Gig]

Arrgh, in Celemine's post above (#30) he first says that you'd need to use a "1K" trimmer, then all references after that are to a "1M" trimmer. I know he initally meant to say "1M", but damnit I saw "1K" and that's what I bought at the store today. Of course I paused and stared at the "1M" for a couple of minutes and wondered if I was getting the right one. I should have bought both--but didn't. Guess where I'm going back later this week?

Sorry bout that! Did just edit the posting with the right "1M" value.

[couppi]

I finished doing all the soldering. Before I fire it up, I just have a few questions.

I can measure voltage from any one of the 3 copper coils around the cpu, right? Is it alright to solder a wire at this point so I can easily read the vcore?

Do I need to set my multimeter to a special setting to measure the voltage through the CPU? Isn't there around 100a of current going through this thing?

[celemine1Gig]

I finished doing all the soldering. Before I fire it up, I just have a few questions.

I can measure voltage from any one of the 3 copper coils around the cpu, right? Is it alright to solder a wire at this point so I can easily read the vcore?
[/img]http://img79.imageshack.us/img79/8264/legsolderst2.jpg[/img]
Do I need to set my multimeter to a special setting to measure the voltage through the CPU? Isn't there around 100a of current going through this thing?

Me personally, I wouldn't add a wire, as it could act like an antenna and add noise to the vcore, but could also be that the influence in negliable.

And you don't need a special setting when measuring VCore. What you do when measuring voltage is measuring in parallel with an internal resistance of the multimeter of about 10M Ohm (10 000 000 Ohm). That means a 10M resistor parallel to the resistance of the circuit. So, no special setting needed, as there's nearly no influence on the circuit when measuring. Current always takes the path of lowest resistance, so why should 100A flow through a 10M resistor, when there's a different path with way lower resistance.

[couppi]

After doing the mod, I'm getting 1.404v idle and 1.395v load with 1.4v selected in BIOS. Great success!

With 1.5v set in BIOS, I'm getting 1.498v idle, 1.486 load. The BIOS voltage reporting is waaay off. Asus probe tells me 1.44v idle, 1.33v load.

[Ron 61]

Congrats, glad for your success.