This guide deals with editing and flashing the VGA BIOS on Nvidia video cards. This guide does not incorporate how to find your card's max stable overclock. see this overclocking guide for that. If you have not made sure that you're card is stable at the clocks you want to set then stop reading this and go and do that! Setting unstable clocks in the VGA BIOS may cause your card to fail to output a signal and force you to do a "blind flash," which is not alot of fun.
This guide does not apply to GeForce FX (5) series or older cards. If you are using one of these... upgrade.
DISCLAIMER: Don't blame me or anyone else here if you screw up your card overclocking. It is unlikely, but still possible. This permanently alters the cards startup parameters. ALWAYS MAKE SURE YOU BACK UP YOUR ORIGINAL BIOS. Also, You WILL void your warranty by flashing the BIOS.
Why would you want to edit/flash your card's BIOS? A good question. Sick of having a million programs start up when loading windows and hogging all your resources? Well this will do away with the need for programs that control your cards clock speeds etc, although you will need them to find stable clocks first. Also if you aren't running windows, this is the ONLY way to overclock your card.
Remember that the min/max clock speeds available in most overclocking programs are based on the clocks stored in the BIOS. Upping the BIOS clocks will move the min/max clocks up also, allowing you to test higher clocks in the "safety" of windows.
Useful sites for Nvidia BIOS files:
MVKTech
techPowerUp
Stuff used in this article to perform the BIOS edit/flash:
- Nvidia BIOS Editor (NiBiTor)
- nvFlash
- Bootable floppy/CD/flash drive
- An Nvidia card (your kidding, right?)
Important notes before you start:
If there is an error during the flash and the program did write to the BIOS, DO NOT REBOOT!! Reflash the original BIOS and make sure the new one is not corrupted. This will save you the hassles of a blind flash from a corrupted BIOS. If the program gives an error, but no write occurred (it should say if there was no write), it is safe to reboot.
If you flash a BIOS with a different device ID (for example, you used a BIOS for a different manufacturer), you MUST reinstall your drivers. If you don't, you may experience image corruption or worse. Remember, as far as windows is concerned you have a different card in there.
Step 1 - Saving your BIOS to an editable .rom file:
First thing you need to do before you can get stuck into editing your BIOS is to actually save it as an editable file.
Open NiBiTor and go Tools -> Read BIOS -> Select Device... and pick which card you want to save the BIOS for. I will assume for this guide that you called it backup.rom
NOTE: The program will warn you if you try to read a BIOS that it can't read properly.
NOTE: If you are flashing another card's BIOS or a custom BIOS and not editing one yourself, skip Step 2 and go to Step 3.
Step 2 - Editing your BIOS file:
Heres where you get your hands dirty. Open the BIOS file in NiBiTor by going File -> Open BIOS... or read the BIOS from the card as stated in the previous section. The program will warn you if you open a BIOS file that it can't read properly. If this is the case, do not continue unless you are willing to risk a blind flash later on! The error message will look similar to the following:
As it says, you can tell it to read the BIOS as a particular generation, which may mean you are ok, but be warned, you may run into problems.
The main page (and clockrates tab) should look similar to the following:
If the integrity indicator is red, do not flash the current BIOS file back to the card! It means it is corrupted. A yellow indicator may occur if the BIOS could not be read properly as stated earlier - it indicates an incorrect checksum and means there could be a problem.
Clockrates Tab
Here you can set the 3D clock speeds, 2D clock speeds and throttling clock speeds. The available clock speeds varies depending on the card, most older cards don't have 2D/3D clocks, and will always run 3D clocks.
3D: The most important speeds. These are loaded when the card is under load, such as in games (or when crunching bungholiomarks ). For overclocking purposes, these are the ones you want to change.
2D: What you are running while reading this. Idle and light load clock speeds. You have no reason to increase these, if anything, you want to decrease them to save power.
Throttle: The clock speeds that are used when switching between 2D and 3D and back. Also used when the card gets a tad too warm These may have stability implications when switching from 2D to 3D and vice versa, so if you have freezes and/or crashes etc when switching, adjusting these may help.
Change amount of active performance levels checkbox: I am unsure exactly what this is supposed to do, but it is for advanced users only, so it is best left unchecked unless you know what it does.
Geometric delta clock: I don't think this needs to be adjusted, but it refers to the delta between the clock speeds of different parts of the GPU.
Voltages Tab
If possible, always use Exact Mode rather than VID Mode as Exact Mode will allow programs such as Rivatuner to correctly report the voltage. This guide only covers Exact Mode as there is no reason to change VID Mode if you change Exact Mode.
Simply select the voltage that you wish to run for each setting. As with clock speeds, older cards will probably only use 3D voltages. There is no reason to increase 2D voltages simply because unless you are looking for bragging rights (which are stupid in this case), you won't have increased your 2D clock speeds. Try decreasing the 2D voltage as with the clock speed to save power. The same applies for throttling as with clock speed.
Extend Voltage Table: Enabling this allows you to select a wider range of voltages, but these are based on experience (by the developer) with your particular BIOS, and are not guaranteed to be accurate. It is recommended that you do not use the extended voltage table unless necessary.
NOTE: Increasing voltages can cause your temps to go through the roof so make sure you only do it in small increments and only if your temps are already good. There is a good chance that it will allow you to clock higher too, so it's not all doom and gloom.
Adv. Info Tab
From MVKTech.net (I would only have said the same thing )
This tab displays additional information and allows you to edit some important IDs manually.
- Device ID: Is the ID used to identify the device. It can also be changed by using dropdown menu Device in the General Info region.
- Sub Vendor ID: Is used to display the Vendor in the General Info area. Changing this may allow you to use vendor specific tools. Note that this is called Sub Vendor ID, because there is also a generic Vendor ID, which is always NVIDIA for NVIDIA BIOSes.
- Sub System ID: This is to make the difference between the different chipsets or GPU's used on the graphics cards.
- Board ID: Is used to distinguish between cards of same chipset. Often flashing tools like nvFlash check these.
- Projected Filesize: Displays the filesize stored in the BIOS, e.g. the size the BIOS thinks it has.
- Actual Filesize: Displays what size the BIOS really has. A mismatch here could be a sign for an incomplete file.
- Calculated Checksum: Shows the checksum calculated from the actual file, this in contrast with the Actual Checksum.
- Actual Checksum: Shows the checksum stored in the BIOS. A mismatch here could indicate corruption or that the BIOS was modified without applying a new checksum.
- Rescan BIOS: Forces the editor to interprate the BIOS again, based on the data in memory. If you e.g. change the Board ID and hit Rescan BIOS, the BIOS will be handled like a BIOS from a different device. When rescanning the BIOS, it is likely that the integrity LED in the Info section will show yellow when you have modified anything on the BIOS. That is because of the modifications and the old checksum doesn't match the new data. A new correct checksum will always be written when the file is saved.
Now my part...
Dual card no execute flag: No idea what this does.
Perf. Table Version: Probably refers to the "Change amount of active performance levels" checkbox earlier, I think it displays what performance level you are currently viewing, whatever that means.
Timings Tab
Note that the following is for advanced users only.
Timings on Nvidia cards works differently than for ATI cards, and this is more difficult to get your head around so bare with me. There are timing sets, 8 in total, used on Geforce 6xxx 7xxx and 8xxx cards. Each set corresponds to a different memory hardware configuration, and the card only uses one set. Clcik on "Autodetect timingset" and you should get a window similar to the following:
Select the device you are changing the BIOS for (assuming you have more than one card, otherwise only one will show up) and click "OK". You should get a window that tells you which timing set your card uses. Click "Detailed Timings" to get a similar window to the following:
Here you can adjust the individual timings for the timing set your card uses. Some timing sets may not yet be changeable. Others will only have some timings available.
On the main timings page click "Test Timings" and you will see this window:
Click "GetTimings" to read the current RAM timings. Click "SetTimings" to write the timings you set above to the GPU registers. This will change the timings in real time, and can cause image corruption, freezes, crashes or blank screens etc. It is only temporary however, and upon reboot, the original BIOS timings will be read into the registers.
Temperature Tab
FX core slowdown temperature: To avoid the questions, I will talk about FX cards here. This is what it sounds like, the temperature at which the GPU throttles due to overheating. It is highly recommended that you do not raise this, and lowering it is not necessary either since I think Nvidia knows how hot their chips can get
Enable 6600GT temp monitor trick: Activates temp monitoring on 6600GT cards (and perhaps others) that have it disabled. If you notice problems, try disabling this as the manufacturer of your card may have disabled it due to problems. May allow fan control with some monitoring programs like Rivatuner.
Disable Temp. Monitoring: Disables temperature monitoring. Also a workaround for 7800 series cold bug when running too chilly.
Core/Ambient Threshold: Temperature thresholds where the card reacts to prevent overheating and damage. The different levels are as follows
- Critical: This is the temp you reach when you pull off the cooler or stop the fan while running 3DMark06. When this temperature is reached, the card is drastically slowed down to bootup clock speeds, until the next reboot.
- Throttling: When the card gets a bit too hot, the card throttles to cool down. This is the temperature at which this happens.
- Fan boost: At this temperature, the driver forces the fan to run at 100%.
Usually the temperatures are Critical > Throttling > Fan boost, but on some cards this is not the case.
Fanspeed: Adjust the fan speeds for each of the three performance levels listed earlier. You may prefer to use 3rd part programs for this if they provide greater flexibility.
Boot Settings Tab
Heres where you can have some fun. Under "OEM signon" you can change the message that comes up when you boot up your computer from the usually boring stuff. "Adv. signon" allows you to change the Nvidia string and version string too, but for short messages, use the "OEM signon".
Display Boot Messages: If you uncheck this, you will not see any message at startup at all.
Display Memory Size: If unchecked, disables the display of the amount of memory onboard. You shouldn't be doing this stuff if you don't already know that.
Engineering release: If you want the e-peen of having an engineering sample but don't have the "contacts", enable this and the string "Engineering release" will appear at bootup.
Bootup displaymode: Unsure what this does as I can't find information on it nor can I view what is in the dropdown (since I have an ATI card).
Text display time: Not sure, but i assume it sets how long the above text strings are displayed for.
Text color: Go figure.
More Bootoptions button: I can't view it nor can I find info on it yet, so I don't know what's in it.
TV Mode: Select NTSC or PAL, depending on where you live.
Now go to File -> Save BIOS... and save the file to something you will remember, for this guide, I will assume you use new.rom.
Step 3 - Preparing to Flash:
Now this is the part that everyone needs to do. Make two bootable floppies (or whatever you want to use). It is recommended that you use bootable floppies, however bootable CDs should work also. You can use Nero to make bootable CDs. Once you make the floppies (the guide will assume you used a floppy so if you use a CD some things will differ) extract nvFlash to them. Make sure both nvFlash.exe and cwsdpmi.exe are on the discs.
Emergency Re-flash Disc: Put your original BIOS file on the disc and write down the name if you need to. Create a text file called autoexec.txt and put this line into it:
- Code: Select all
nvflash.exe -4 -5 -6 -a -y backup.rom
Main flash disc: Put your original BIOS file and the new BIOS file on the disc and write down the names if you need to.
Step 4 - Flashing:
Stick your floppy in and reboot. Go to the BIOS (of your motherboard not your card of course) and make sure you have your floppy as your first boot device. Reboot again and DOS will load from the floppy. Next type in:
- Code: Select all
nvflash.exe -4 -5 -6 new.rom
If there were errors and the program did write to the BIOS, don't reboot. Flash your backup BIOS again using the same code as above but with backup.rom. Reboot after a successful flash. If you get no signal or something doesn't look right, just boot from your re-flash card (which will reboot the PC automatically once it's done) and go back to windows and edit your settings to make sure everything is ok.
Open up Rivatuner or something else and verify that your changes took place (most should have, but some like voltages and fan settings may not be possible to change due to hardware limitations).
Credit goes to MVKTech for some of the images used in this guide, especially windows/menus I can't access.
I have an ATI guide to complement it as well, I'll get around to posting that soon.
News
Site map
SitemapIndex
RSS Feed