Based on the guide by Shamino from Vr-zone, I decided to go ahead with this mod as i need a little extra juice out of graphics card. For those cards which doesn't have any external power source, this mod should be ideal. I didn't like the idea of drawing the power from the PCI-E slots.

how's the result ?
you only can get 3.3V through the 24 pin ATX right ?

Haven't tested it out yet. Currently doing a little mod on my cascade cooling. You can get the 3.3v either from the ATX pin or SATA molex connector.

You could also directly solder it to the pins under the ATX socket, saves having a loose wire hanging around.

yes...but i wouldnt want to share it with the mobo....coz PSU has got split rails....one rail for mobo and another rail for the GFX......

If u mount wrong pins . The mobo crashed ?

Doesn't serve much purpose if you ask me.

Anyways 3.3v is kind of pointless since most graphics cards predominantly just step down their supply from the 12V line, it might be used for the memory, but that doesn't really warrant a line of it's own. 5V probably for on board secondary logic, neither important. Last if not least, Kirchoff's law dictates that the sum of all currents is equal to to all the currents of it's branches, thus the pins of the PCI-E slot might not be able to take that amount of current.

Seems like a dangerous affair ripped out of a the PCI-E whitepaper and a few datasheets.

Wrong pins....you'll kill you card...simple...

This mod is for overclocking purpose. It does help as sometimes the PCI-E slot cant provide adequate current to the card from those tiny lines. So this mod feeds the card directly from the PSU...hence higher stability. I added the 3.3v as i measured from the pins there is 3.3v line feeding the card. But no 5V. So therefore only 12v and 3.3v is required for graphics card.

Well, extreme overclocking is a risky affair anyway....as this mod is done at ones risk.

I disagree, those tiny lines are still in use because the slot it self still uses them. And as current goes up, we all know what happens when it gets too high leh . On the board itself, the power is delivered via power plane, which is much better than wires.

I suggest xbitlab.com's method, which involves modding the graphic card to deliver power through it and thus isolating it from motherboard and feeding it directly via the PSU. Solder a line to the proper pin on the CG, then seal it off with a small strip of tape so it doesn't take power from the slot. I seriously salute anyone that's gonna attempt that.

Hehe....I've done this mod before but to an AGP Slot. The power are still routed through tiny lines on the card to the mosfet, I didn't get much improvement. The best method I found is to solder the power lines directly to the card itself and get some boost in OC.

Some pic of my mods. This is some old stuff.....long time don't do these kind of stuf already