VCORE mod for MSI K8N SLI mobo needed!!

**tombman** · 01-22-2005, 05:08 AM

Hi, vdimm is done by ocz ddr booster, but i NEED more voltage to the cpu!

Can it be done? Has anyone done it? Pics?

HELP!

**Tom Holck** · 01-27-2005, 03:04 PM

Originally Posted by tombman

Hi, vdimm is done by ocz ddr booster, but i NEED more voltage to the cpu!

Can it be done? Has anyone done it? Pics?

HELP!

Haven't tried myself yeat

Be carefull M8

Edit: now the picture is right.

**SmokeyTheBandit** · 01-27-2005, 10:45 PM

Originally Posted by Tom Holck

Haven't tried myself yeat

Be carefull M8

Yes this should be the mod altough it is extremely tiny ..... damn ...

Vdimm mod maybe ?

**Tom Holck** · 01-29-2005, 11:50 AM

This works:

VR 20k ohm, turned to about 14-12 k ohm.
It will give you a little under 1.85 volt. If you try going higher the OVP shot down. Then go a little back. Then you have your max corevolt.

**SmokeyTheBandit** · 01-29-2005, 02:59 PM

Originally Posted by Tom Holck

This works:

Nice thanks tom this is far more easy to solder than pin 9

:banana4:

**A_X** · 02-05-2005, 06:01 AM

Sorry, I'm a bit of a noob when it come's to modding. But what am I actually supposed to do with that VR 20K ohm? Could somebody explain it a bit further for me?

Thanx

Edit->

Nevermind.. I took a look at my board and this is WAY to small for me to solder....

**Dumo** · 02-06-2005, 11:26 AM

Will try, since no bios released yet...

**JohnnySK** · 02-06-2005, 01:05 PM

Are you sure about the 20k ohm VR? Anyway, I will be buying the 20k VR tomorrow and wait for your reply.. Could you also please explain how you came up with the 20k VR? This really fascinates me and I would like to know a little bit more in detail.

Thank you!

john

**A_X** · 02-06-2005, 10:49 PM

Originally Posted by JohnnySK

Are you sure about the 20k ohm VR? Using a multimeter I got 1,2m ohm on the C5 - isn't 20k too little?

Anyway, I will be buying the 20k VR tomorrow and wait for your reply.. Could you also please explain how you came up with the 20k VR? This really fascinates me and I would like to know a little bit more in detail.

Thank you!

john

Please post pics of your mod!

Thanx!

**JohnnySK** · 02-07-2005, 01:30 AM

Just wanted to make sure that I will do the right thing..

I am supposed to unsolder the C5 capacitor and solder the 20k ohm VR instead? Or connect it parallel to the C5 capacitor? Just need this info and I will get going with the mod

Fast relies are welcome,I am just waiting for this info...

john

**persivore** · 02-07-2005, 01:36 AM

You connect one end of the VR to the pin marked on the pic and the other end to a ground point (e.g a screw/mounting hole)

**Kane** · 02-08-2005, 11:08 PM

Has anyone tried this mod, and does it work? If I do it. Should I just watch the voltage in bios while I turn the VR. Set it to max in bios, and then turn it until it shows 1.7v. That's the max I want to be able to give it. A bigger picture that shows me where to solder would be nice. The small picture is good, but I have no idea where on the mainboard it is.

**Tom Holck** · 02-09-2005, 06:52 AM

Originally Posted by Kane

Has anyone tried this mod, and does it work? If I do it. Should I just watch the voltage in bios while I turn the VR. Set it to max in bios, and then turn it until it shows 1.7v. That's the max I want to be able to give it. A bigger picture that shows me where to solder would be nice. The small picture is good, but I have no idea where on the mainboard it is.

It works! right to 1.85 volt. Then OVP shoots down.
Yes, set the VR on max 20 k ohm boot and use bios corevolt or software in windows to ajust.

The area on the small picture is close to the CPU

**Kane** · 02-09-2005, 07:03 AM

Okay, Thanks Tom

I'm always nervous when vmodding

Will try this mod this weekend. Other then the low vcore, I really like this card. Will also (hopefully) get my second 6800Ultra this weekend. Looking forward to running some benchmarks

**A_X** · 02-09-2005, 01:20 PM

Originally Posted by Kane

Okay, Thanks Tom

I'm always nervous when vmodding

Will try this mod this weekend. Other then the low vcore, I really like this card. Will also (hopefully) get my second 6800Ultra this weekend. Looking forward to running some benchmarks

Good! Please post pics! I'm probably even more nervous then you..

**JohnnySK** · 02-10-2005, 02:19 AM

Hi ppl.. so I've done the mod! Don't have any pics as I don't have a digital camera. Unfortunatelly, it doesent seem to work

Turning the 20k VR while in BIOS I get to around ONLY 2k and the OVP shuts down my PC - but I can't see any increase in voltage at all? Neither CPU-Z nor BIOS info screen show any increase in voltage.. Have I done something wrong?

Oh yes, be carefull when soldering - by mistake I unsoldered the C5

Well ppl, so can someone enlighten me what could be wrong? Other than that, the MB workx fine even after the solder job..

john

**A_X** · 02-10-2005, 05:38 AM

Hmm that sucks.. I just got myself a 20k VR today...

Edit:

@JohnnySK: Perhaps it is not connected to a good ground point?

**JohnnySK** · 02-10-2005, 08:40 AM

Well the OVP does power-off the system so it must be doing something.. Any gurus can help??

**persivore** · 02-10-2005, 11:06 AM

have you tried reading the voltage using a DMM? You could also check with a DMM if the point you solder to on C5 is connected to pin 9 on the chip.

**JohnnySK** · 02-10-2005, 11:58 AM

Yup,it's connected to pin9..tried that after I soldered the whole thing. Where from should I read the actuall voltage? Could you post a pic plz?

**persivore** · 02-10-2005, 12:31 PM

You should be able to get a reading from one of the inductor legs around the CPU socket. You could also try to get a reading from one of the MOSFETS, but the voltage might be slightly lower than the true Vcore. If your careful, you might be able to get a reading from pin 16 of the IC too.

TBH, after looking at suggested circuit diagrams in the datasheet for the voltage controller I'm a bit doubtful about the mod using pin9 (feedback) because it doesn't appear to be connected to the output voltage in any way. To me, Vsense (pin12) would be more logical to use becasue it is connected to the output voltage, but that might depend on cutting traces. It depends how closely the motherboard designers have followed the refence circuit diagram tho.
If it has been said that the mod works tho, I guess that it will work ok using the feedback pin.

**A_X** · 02-11-2005, 09:24 AM

Got it to work yet?

**OneProdigy** · 02-11-2005, 01:48 PM

Just to clear things up...

Pin9 of the ISL6566 regulator is marked wrong in the pic above!
Here's the correct solder point and some shots of the finished mod.