Simple pencil trace to increase voltage – Ji Kuang
The Abit NF7-S rev. 1.2 comes with higher adjustable chipset voltage to help overclockers hit greater FSBs. However, the max of 1.7v is a real let down for high FSB seekers. Thus many resort to soldering a resistor on the pin of an IC chip to help increase chipset (VDD) voltage.
However, for those with a phobia of soldering, here’s an easy way out. All you need is a pencil and a multimeter. It’s a real simple mod that should take at most half an hour. All you need to do is to pencil the correct resistor. Yep, it’s the good old pencil trick again!
Step 1: Locate the spot to measure VDD/chipset voltage. There are basically 2 spots to choose from as shown here in this picture:
Spot 2 is about 0.1v higher than spot 1, as you can tell by adjusting your chipset voltage in the BIOS. There are some who argue that spot 2 is the actual chipset voltage spot, but others go according to spot 1. Spot 2 may be a more convenient spot for those with a bulky AGP card.
Step 2: Power on your PC, enter your BIOS and set your chipset voltage to 1.4v and save upon exit.
Step 3: With your PC powered on and in the BIOS screen, carefully measure your actual VDD with the multimeter. The way to measure would be to place your red line of your multimeter at the spot of your choice and the black line of the meter to ground, which can be your PCI slot handle. It should give you a value near to 1.4v, maybe 1.3+v or so. Power down your PC.
Step 4: Locate the resistor to pencil. It would be easier for you if you remove your whole motherboard.
Look in this picture and spot the resistor circled in green. Got it?
Step 5: Get a multimeter and measure the resistance of this resistor. I’ve measure 3 boards and they get around 572-578 ohms.
Step 6: Whip out your sharpened HB/2B pencil.
Step 7: Get your palm in position and start to pencil along the side of the resistor (The RESISTOR and not on the motherboard!).
See the line I highlighted in green? Thats the way to do it. Be careful not to accidentally pencil the resistors nearby. One “U” stroke, stop and measure resistance. Repeat till you get the resistance you want/need.
Here’s a guideline for the resistance.
About every 30 ohms drop yield a +0.1v increase.
When I dropped to 504 ohms from 572 ohms, VDD increased from 1.38v to 1.54v. I’ve had it all the way down to 424 ohms which gave me 1.83v when set at 1.4v. I would say go no more than +0.2v higher than the default maximum of 1.7v if you’re just cooling the Northbridge with some average heatsink fan like an ORB.
With a better heatsink fan like one for a CPU, probably 2v or so is fine. I’ve been running 2.14v (as measured at spot 1; Spot 2 shows 2.24v) for many days running Prime 95, games and so on without problems, but I’m watercooling the Northbridge as seen here:
And yes, it still continues helping my FSB/Ram at such a high voltage.
Also get a heatsink or heatsink fan for your southbridge which gets hot too.
Step 8: Power on your PC and measure your same spot again. How much increase did you get? If it is not enough an increase, add on some more graphite to reduce resistance by some more and measure the resistance before turning it on again.
If it is too much then rub off some graphite with an eraser to get a higher resistance. Tweak it till you get the increase you want. Once satisfied, carefully tape over the penciled area to prevent graphite from being blown off or so. Simple, right? And if you need it back to default, just rub off the graphite.
I got 238 FSB from this mod and was able to run at CAS 3, 3, 2, 2.0 at this speed:
Things to note:
- This only applies to NF7-S Rev. 1.2!
- Never try this without a multimeter!
- Always measure the resistor’s ohms before turning on the PC.
- Don’t ever drop below 410 ohms here.