As for the Vgpu I didn't even bother looking up the hardware-based modification as there's a simple tool available to increase the voltage through the VID-mode of the voltage regulator. No, it's not the MSI Afterburner software which, in the end, limited me both in terms of voltage options and frequency options. Instead of the Afterburner software, I decided to use the same application we've used when testing the Asus GTX285 Matrix. Let's go back a few months:
As for the application of this I2C feature. I'm not really a very good software programmer, but I was lucky enough that Snot_Aap, a Dutch overclocker, had already programmed this application for the MSI Lightning GTX 260, which was used at MSI's MOA EU 2009 final in Munich, which has been covered by Madshrimps not so long ago. All I had to do was check and partially re-write the code to make it work for the Asus Matrix GTX285!
Link (right-click and save): MadMatrix.rarHow to use:
- Place the 'Madmatrix.bat' file in your rivatuner folder.
- Double-click the 'Madmatrix.bat' and enter the HEX value matching the prefered voltage(*)
- Make sure you typed the right HEX value and enter 'Y' or 'yes' and press enter.
- Check the commands that will be run and press enter.
- Check the voltage with a multimeter on the card or with the Asus software utility(*²)
(*): The voltages stated in the utility are not the only ones you can use. As said before, there are 256 combinations, so you will have a look in the datasheet (P.15) if you want to apply a different voltage. Note that the voltage has to be indicated by its HEX value, so you will need a BIN to HEX converter to translate VID table. Also note that this is a workaround for the OVP problem: by using the software utility, you will not trigger the OVP. OCP, Over Current Protection, still is an issue though.
(*²): This software has compatibility problems with the Asus software as both re-write the VID settings. Please, do NOT use the Asus utility to change ANYTHING (frequency, voltage or fan speed) if you're using the Madshrimps utility. If you use our utility first and then apply anything in the Asus utility, your voltage selection will have been reset!
The only modification left was the Vmem modification which is also quite important as you will find out later on in this article. For creating the picture, we've used the extremely large picture hosted on TechpowerUP.com