Originally Posted by K404
Graphite conducts *slightly* so if you shade across a resistor, it sets up a parallel resistor network, which is the exact same as soldering a potentiometer across the ends of the resistor.... BUT pencil is cruder, with less control + precision, and can be affected by nearby airflow... ie... the graphite gets blown away.
Heavier shading decreases resistance, hence increases voltage.
You can get pretty fine control with harder lead, and you can tape up the area afterwards. I prefer to use a razor fine tip to shade the side/corner of the appropriate resistor and avoid putting graphite on any surface facing directly up (as that's what the tape sticks to).
I've had pencil mods on some cards last upwards of two years without issue.
Originally Posted by gaddster
Good work Meaker. I've got one of the sapphire rev 2 non reference 5850's, how much would this pencil mod increase my 3d load voltage too? Is it a case of more graphite = less resistance therefore higher voltage or just the fact of 'connecting' the points with any amount of graphite?
Also in your youtube vid you use a ground point on the card, I take it any ground point will do ie case or bracket of the card?
Thanks in advance
It's variable, depending on how much graphite is deposited.
You do not want to completely short the points, that will kill the card.