A few questions

[Arkangyl]

I'm currently running a MSI K8N Neo2 Platinum with the vDIMM = 3.3v line mod (using Mushkin Blue UTT). ATM this is working out alright but I have dreams of more vDIMM.

I know one option is to raise the 3.3v line's voltage.
Another would be a DDR booster.

however I like to do this stuff myself :clap:

What i want to do is create a circuit that takes the 5v line from the 24 pin connector (sanded down the 20 pin female on the board so i can just put a 24 pin in there :P ), resist it down to 4v. Throw a cap or two to keep it clean and then add some sort of VR to adjust the voltage.

To do this I need to know first and foremost; what will the amp draw on the 5v line be?

Secondly, does anyone have any good links to similar projects?

thanks

Ark

[celemine1Gig]

Here's something similar:

http://www.xtremesystems.org/forums/showthread.php?t=72215

[Arkangyl]

thanks celemine1Gig. I saw that mod and it's basically what i want to do.

however where are you actually controlling the voltage? in the BIOS? and could you give me a circuit diagram to that option part with the diode board? I'm not sure I'm making proper sense of that in the picture

I see

==||=========||___GROUND
==||=========||

==||=========||___5v line
==||=========||
| | | |
4.3v=||| ||| Diodes


Addmitting that I'm teaching this to myself as I I'm going; how does this circuit work? I dont see where the 4.3v out gets connected to, well, anything really. and where do i add in the cap and ground it?

thanks

[celemine1Gig]

First you need to find the Vdimm Mosfet that gets fed by 3.3V. You use a multimeter with the continuity test function enabled to do so. Just connect one lead of the DMM to the 3.3V line of the ATX connector and then try the Mosfets near the Dimm slots to find the correct pin (should be a source pin).

After you found that pin, you have to look up the datasheet of the mosfet to see, if it's rated for voltages above 3.3V (very likely). Then you have to lift the MOSFET leg that was formerly connected to 3.3V on the PCB, thus it doesn't make conact to the 3.3V line anymore. All you have to do then is to solder in a thick cable from the ATX 5V line to this pin. The capacitor and the diodes in my guide are fully optional (why does nobody read the guide carefully enough to see that).
All the capacitor does is to smooth out voltage spikes (not really needed as the 3.3V line is also connected to the mosfet without any cap in between) and all the diodes do is drop the voltage slighty by about 0.7V, in order to decrease the power dissipation from the MOSFET. 5V is the input from the ATX connector. Ground is needed to connect the capacitor between gorund and 5V. And the 4.3V is the output of the diodes (you would connect that to the MOSFET leg). That's all.

You control the voltage with the same VDimm-Mod that you would use with Vdimm fed by 3.3V. ;)

[Arkangyl]

ahh, thanks celemine.

and i did see that the diodes were optional; i wanted them in there ;)

as for the rest of the mod; makes sense but the normal vmod on the Neo2 is a PITA (trace cutting); I was looking for something a tad easier with less risk of killing the board

[celemine1Gig]

ahh, thanks celemine.

and i did see that the diodes were optional; i wanted them in there ;)

as for the rest of the mod; makes sense but the normal vmod on the Neo2 is a PITA (trace cutting); I was looking for something a tad easier with less risk of killing the board

Well, cutting a trace isn't that hard if you got a DMM. Just use the continuity test again. This way you can cut carefully and cut several times, measuring after each cut, thus the risk of cutting too deep is really low.

But anyway, do you have a link to the VDimm-Mod? I'd like to see it (will do a search on my own later, but just in case I don't find it).

[Arkangyl]

http://www.hardwaredome.nl/reviews/view/18/1

vDIMM mods are all in there (I've gotta do the rest soon :p)