SK8N Vdimm mod

[Caprid]

This probably won't be a very popular board with the Nvidia 250 chipset replacing the SK8Ns 150, but it's all I have to work with for now. Figure someone might be interested.

The Memory Voltage regulator is a Richtek RT9202
Datasheet
It's located on the top right of the board above the ATX connectors.





You want Pin#6(red circle) to your VR to ground. The 'red X' is your Vdimm measurement point, on the bottom of the resistor.

Now you got some voltage to tighten up those timings on that Registered RAM

[saaya]

i thought the 250 is the 150 with a better sb?

[Caprid]

It'll also get a new hypertransport link. It'll use 16-bit/1.6Ghz upstream and downstream for a full 6.4GB/s of total bandwidth as opposed to 16-bit/1.6Ghz up and only 8-bit/1.6Ghz down for 5.2Ghz. That should bring the HT bus up to par with the VIA boards. VIA makes sure you know about it too, LOL

http://www.viaarena.com/?PageID=336

[charlie]

Caprid,
Thanks for your work...
C

[Stinger]

And what VR do you use?

[Caprid]

I'm using a 15turn 10K pot for the Vdimm, anything bigger has to much of a voltage swing and is hard to fine tune(killed a few boards that way)

The SK8N has some serious voltage issues. I set the Vcore to 1.75v in the BIOS, with no Vmods and my Pc power and cooling 475 exploded...flames and all. I was talking to the Pcpc rep about an RMA and they are going to do a diagnostic evaluation on the PSU to see what happened.
Got the new board back from RMA, set the Vcore to 1.75v and it just cuts off, I'm not going to mess with the Vcore untill I get some good cooling on the CPU.

If someone still wants to mess with it, the Vcore IC is an Analog Devices ADP3166 it's located right behind the ATX connector beyond a row of capacitors. According to the Datasheet the FB sense pin is #8 a 25K-50K ought to do the trick. I don't know were to get the reading off the board yet, like I said I'm a little gun shy with this one. Also don't trust the BIOS I'm getting 11.13 for the +12v, 5.26v for the +5V and 3.17v for the +3.3V

[charlie]

Caprid,
Anything more on your Sk8N mods??
C

[xgman]

Originally posted by Caprid
I'm using a 15turn 10K pot for the Vdimm, anything bigger has to much of a voltage swing and is hard to fine tune(killed a few boards that way)

The SK8N has some serious voltage issues. I set the Vcore to 1.75v in the BIOS, with no Vmods and my Pc power and cooling 475 exploded...flames and all. I was talking to the Pcpc rep about an RMA and they are going to do a diagnostic evaluation on the PSU to see what happened.
Got the new board back from RMA, set the Vcore to 1.75v and it just cuts off, I'm not going to mess with the Vcore untill I get some good cooling on the CPU.

If someone still wants to mess with it, the Vcore IC is an Analog Devices ADP3166 it's located right behind the ATX connector beyond a row of capacitors. According to the Datasheet the FB sense pin is #8 a 25K-50K ought to do the trick. I don't know were to get the reading off the board yet, like I said I'm a little gun shy with this one. Also don't trust the BIOS I'm getting 11.13 for the +12v, 5.26v for the +5V and 3.17v for the +3.3V

If you read the 12v in Windows, it is 12v or over. This reading in bios doesn't make sense. Also the bios power management is just plain wierd. Sometimes the Power led light comes on before you push the power button. Sometimes it powers up just from turning on the power strip. It doesn't seem to be able to send the monitor to sleep in WindowsXP. I may try both of these mods. Certainly the ram and the temps are pretty low on a water block so maybe some more vcore as well. I'll lket you knwo how it goes.

I have set the Vcore on my board to 1.75 since I got it and with bios 1003-007 or ,007 I have had no problems with that. I am running a True Control 550w PS with the dials turned all the way up.

[xgman]

1004.001

ftp://www.asus.it/pub/ASUS/mb/socket940/sk8n/

also

http://www.aida32.hu/aida32.php

"extended support for 64-bit AMD processors"

[xgman]

Is 3.07v too much for Corsair with winbond "ch" chips or is it OK to leave it there for every day. Or should I notch it back to 2.97v?

[tombman]

Caprid... can you tell us how to do the vCORE mod on the sk8n?
(i saw your pifast41 entry on hexusnet- there you got 1.925vcore...)

HELP

[Caprid]

As I said above it's the Analog Devices ADP3166 I've done the mod and it works. It's pin #8 to your Variable Resistor to ground. You can check the Voltages in the BIOS. I used a 47K pot, but you'd probably be better off with a 25K.....the 47k is kinda touchy. My sister has my camera ATM, if someone can get me a pic of the board around the ATX molex connectors I'll show you which IC it is.

[tombman]

Originally posted by Caprid
As I said above it's the Analog Devices ADP3166 I've done the mod and it works. It's pin #8 to your Variable Resistor to ground. You can check the Voltages in the BIOS. I used a 47K pot, but you'd probably be better off with a 25K.....the 47k is kinda touchy. My sister has my camera ATM, if someone can get me a pic of the board around the ATX molex connectors I'll show you which IC it is.

Ok, thx, but i´ll wait ´till you get that cam

Btw, is your FX-51 still working? Or did you fry it?

[charlie]

What's the correct initial setting for a 25K Pot for the Vcore mod??

C

[Caprid]

Morning charlie,
Set the trimmer to max resistance. Then I set the BIOS to 1.5v and go from there. There seems to be an OVP somewere, as the board won't POST after saving changes to the BIOS or a soft reboot. Just hit the on/off angain and it will come back up.

[charlie]

Thanks Caprid!!
Da*n that's a small mod...how'd you do it?

[Caprid]

Yeah that 28pin IC is a little bugger lol
I used SMD grabbers for that one...don't think my soldering skills are up for something that small.

[Caprid]

When I was looking for the Vdimm readout that was the only spot I could find. I saw somewhere that you can get the reading off the mosfet on top, but mine didn't change with the changes within the BIOS