Originally Posted by Choggs396
Sweet. I'd really like to try it, but I'm a little hesitant in fiddling with the BIOS of a $300+ video card. Maybe if I saw some examples or other people's successful results.
It seems these days the success rates are much higher, I googled some and found interesting results... Most believe that max(for the 8800 series cards) vCORE is stock
vCORE any higher and a resistor mod is needed first. I know this volt-mod is kind of a tangent, sorry
. But Vmod + Nibitor custom bios sounds nice.
This guide applies only to G92 based nVIDIA 8800GT and GTS reference boards. If your card has different layout feel free to report here, and, if possible post clear pictures of the card.
Higher resolution image @ Imageshack:
- stock vGPU voltages for this card are 1.05v (2D idle) and 1.15v (3D load)
- stock vMEM voltage for Qimonda GDDR3 (HYB18H512321BF-10) is 2.0v Â±5%
- vMEM mod has been deemed almost useless as Qimonda GDDR3 does not OC any better at higher voltages
- 1kΩ variable resistor can be used for the vGPU mod in order to maintain minimum voltage close to stock. 500Ω VR will be more accurate to tune but it will also force vGPU slightly higher than stock even when the VR is tuned for lowest vGPU = maximum resistance.
- vGPU pencil mod turned out to be virtually impossible
- usage of a multimeter is required for tracking the vGPU
8800GT features the same vGPU (Primarion PX3544BDSG) and vMEM (Intersil ISL6549CBZ) controllers as 8800GTS and GTX, devising the mods shouldn't be much of a problem eventhough the PCB layouts aren't the same, the controllers' sense pins are...
Since I don't have a G92 based card I'm going to need some assistance from people who actually have the card for detailed pics of some areas of the card [done] and some resistance measurements [done].
A guide for performing the mod via variable resistors or pencil can be found in this thread/post once required data is available. Alternately, as it is likely people are already working on the mod it might happen that all will only find here is an external link to the mod instructions (if such a guide pops up before this thread delivers).
Discussion about the mod sparked in FUGGER's G92 thread here.
Originally Posted by largon
Need clarification on the existence of certain traces and few resistance measurements, see attachements.
There should be traces between points 1, 2 and 3. It certainly does look like there is a trace between 2 and 3, but is there one between 1 and 2? = if there are traces between 1, 2 and 3 then resistance between each is ~4-6Ω.
[EDIT: traces are there, pic courtesy of dinos22, thanks]
Resistance between points 2 and 4/ground?
[EDIT: 11Ω / 15Ω, thanks dinos22 and metro.cl!.
Strange. Measured value should definitely be ≥ 35Ω, gonna have to look into this... ]
Second pic: [EDIT: new pic]
Resistance between points 7/ground and 8? Should be same as ISL6549CBZ pin4 to pin7 (ground).
[EDIT: ~610Ω, thanks metro.cl!]
Also, is it just me or does google really suck these days? I swear many of the top few search results I get now are completely BS...