Join Date: Nov 2007
Location: Ottawa, ON
Rep: 266 (Unique: 199)
|nVidia BIOS Editor (NiBiTor) enables you to change the sign-on message text & color, GPU & memory clocks, hidden features like SBA (Side Band Addressing) and much more.
NiBiTor is the original and definitive BIOS tweaker that supports the latest nVidia graphics cards. NiBiTor allows graphics card enthusiasts to have full control over advanced features and functionality found on firmware of supporting cards.
Can this program alter core and/or memory voltages on an 8800GTX?
The next tab that we can find in NiBiTor are the Voltages that are set within the BIOS. You get a clear view on the actual values of each voltage and also the ability to change those according to your needs.
On most cards you can change the voltages using either the Exact Mode or the VID Mode. It is recommended to use the Exact Mode if or when possible. Depending on the amount of performance modes your card has, you can select the voltage applied to the GPU in each mode. The 3D/Thrtl/2D modes are the same as mentioned with the clockrates.
If you only have one mode to edit e.g. 3D, the voltage set there is always used, regardless if you are running 3D or desktop. When working in Exact Mode, the voltage identifier of one performance table entry is modified, this identifier is used by the driver to find the corresponding VID in the voltage table.
The advantage of this editing this way is that monitoring tools can show the correct voltage, and modified BIOS files can be interpreted correctly to show the right voltage.
The Extend Voltage Table box allows you to automatically extend the voltage table of the BIOS, and tries to give you all voltages for a selection that your BIOS supports. Note that this is based on experience with your cards BIOS, and is not fully sure to be accurate.
In VID Mode, you can change each entry of the voltage table. Each voltage table entry has a voltage identifier, which is shown left, and a VID. You can select the VID assigned to each identifier. Behind each VID its own orginal voltage identifier is displayed as a level of help.
Note that the assignment "Voltage Identifiers <> VID" is only valid when using a BIOS has not been editied using this mode before. When the amount of possible VIDs in your BIOS is bigger than the number of entries in the voltage table, the additional VIDs can be selected but their voltage is labled as "?.?V", because there is no assignment to a voltage identifier for them.
Using Extended Labeling will force the editor to guess the voltages for unknown VID's, based on experience with your BIOS. In the same way like the Extend Voltage Table option, this is not 100% reliable.
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.
|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!]
|Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)|