Today I am here to tell you, how to overclock your Fermi based GeForce card.This tutorial is written for MSI GeForce N460GTX 1GB OC edition! You can change some values according to your card, but it's a risky. nVidia didn't provide support for overclocking in Linux. The only option is to modify the BIOS of graphic card. I am going to explain this mod on my MSI GeForce N460GTX 1GB OC edition.
For this mod you will need these things:
# dd if=FDSTD10.IMG of=/dev/sdx bs=512
When all is complete, decompress nvFlash utility and copy it's content to the USB drive (IMG is 10MB big to have some extra space for utils). Now you can reboot your system and boot from your USB drive. When command prompt appears, run this command to backup your BIOS:
C:\> NVFLASH.EXE --save BIOS.rom
Now you can restart your computer and boot your Linux. It's time for modify your BIOS. Make sure you have your BIOS backuped! Run NiBiTor (with wine works perfect) and open your BIOS file.
Integrity MUST be green. That means that your BIOS file is OK. Go to Tools->Fermi Voltage. You should see this:
|Fermi Voltage Editor - stock values|
- Limit: 1.15V
- Setting 2, Tab 0: 1.0125V
- Setting 2, Tab 1: 1.1V
|Fermi Clock Editor - stock values|
- Line 15, Tab 5: Memory frequency, mine is in nVidia reported as 3600MHz, here is 1800.
- Line 15, Tab 3: Shader frequnecy.
- Line 15, Tab 4: Bumped shader, calculated from Shader frequency.
- Line 15, Tab 11: Bumped shader, calculated from Shader frequency
- Line 12, Tab 5: 2050MHz
- Line 15, Tab 5: 2050MHz
|Memory frequency changing|
(Line 15, Tab 4) divided by (Line 15, Tab 3)
In this example, it is as
1538 / 1451 = 1.06
Our bumped multiplier is 1.06. Now we can set desired shader frequency (1700 MHz) in Line 15, Tab 3
|Shader frequency changing|
and calculate bumped shader with our formula as:
1700 * 1.06 = 1802
Here is used multiplication!!! So now, set Line 15, Tab 4 and 11 as 1802.
|Bumped Shader frequency changing|
C:\> NVFLASH.exe new.rom
When asks, say "y". After all is done, reboot your computer and check your new overclock.
C:\> NVFLASH.EXE old.rom
Wait about 10 seconds, pres "y" and hit Enter. After 30 seconds, reboot your computer. Your old BIOS should be resotred. If it's not working, take your card to your friend, who has two PCIe slots, plug it in second slot and flash your BIOS using his card for display. Here is my original BIOS file and modified.