[SIZE="+1"]Required Tools[/SIZE]
- If you will be modding your own bios, you will need a utility to get a copy of the bios from the card. ATITool can be used for that.
- RaBiT is an essential utility for any these mods. As of this posting, the current version is 2.0a and may be downloaded here: http://www.techpowerup.com/downloads/283
- For some mods you will also need a hex editor; any will do just fine. One I've found that looks like it would be very easy to find the right location for the values to change can be found here: http://www.mh-nexus.de/ It has a heading at the top which shows the offset for columns, not just rows. It also looks like a decent hex editor overall.
In addition to these tools, you will also need to know how to flash the bios after performing the mod. Instructions for that may be found elsewhere on this site.
Important note: For any of these guides, I recommend reading through the whole thing before attempting to perform the mods.
If you are not comfortable with performing these modifications yourself, there are many others who are also familiar with how to do these, especially after I posted this guide.
[SIZE="+1"]Mod #1 - Changing the Number of Active Pixel Pipelines[/SIZE]
This type of mod can be used for increasing the number of pixel pipelines to all of the ones that are available on your card or also reducing the number (of course, only for testing purposes
). Here are the steps to performing this mod:
- If you are modifying your own bios, get a dump of the bios if you haven't already done so (this can be done with ATITool).
- Make a copy of the bios you are editing.
- Open the copy in a hex editor.
- Go to the value at offset 0x7A. If the bios is your current bios, the value at this location should look the same as the CONFIG_ROM_FUSES value that will show up in ATITool if you hold shift when clicking the settings button, except that the first two and last two digits will be switched. Below is an example of what you might see. A red box was added to show the location of the value.
- For the byte at 0x7A, leave the first digit intact and change the second digit to one of these values:
0 = zero pixel pipeline quads disabled (16 pipelines enabled)
1 = one pixel pipeline quad disabled (12 pipelines enabled)
2 = two pixel pipeline quads disabled (8 pipelines enabled)
3 = three pixel pipeline quads disabled (4 pipelines enabled)
For example, to change the one shown above from 12 pipelines to 16 pipelines, change the second digit of the value to a zero and this is what it should look like:
- After changing the value, save the bios.
- Open the modded bios in RaBiT. It will warn you that the bios may be corrupt. When this message appears, click "Yes" to continue.
- Save the modded bios. Overwrite the file you just opened, there is no need to create a new file. This step is to fix some checksum and CRC values in the bios so that it will work right.
- The modded bios is done.
After correctly flashing the modding bios to the video card, the last digit of CONFIG_ROM_FUSES will change to the same number you picked in step 5, and the number of disabled pipelines will be either how many you picked or how many are disabled in hardware, whichever is higher.
[SIZE="+1"]Mod #2 - Changing the Name and/or GPU Type[/SIZE]
This type of mod can be used to change the name detected for your card and/or the type of GPU detected. Changing the name just gives your card a different name, but does not change performance. In general, you should stay within the same general card class when changing it since it can change the detected GPU type if you don't (X800 should stay X800, X850 should stay X850).
Changing the type of GPU detected to R480 can increase performance for cards that have R480 chips but do not get detected as such (primarily some X800 GT cards and some few X800 GTO/GTO² cards). The GPU type should be kept the same for cards that do not have R480 chips as it can and likely will cause problems on non-R480 chips. (For more information on this and for some pre-modded X800 GT bioses, look here:
Performance boost for X800 GT cards with R480 GPU)
There are a few of ways to identify whether the GPU is R480 or not:
- If ATITool or other utilities say it is R480.
- If that is not the case the most obvious way to find out, of course, is to take off the heatsink and look at the GPU. If it is R480, it will say so.
- Another way is to look at the fuses data in ATITool that shows up when you hold shift and click on settings. If it is R480 or R430 then CONFIG_DIE_FUSES will look like 0xFFFF?FFF and CONFIG_SUBSTRATE_FUSES will look like 0xFFFFFF9? where the "?" can be any digit. After you determine that it is R480 or R430, to distinguish between the two you can check how high the GPU can be safely overclocked. Many (or most) R430 chips cannot reach 450 MHz and all (as far as I know) cannot reach 470 or above. If your's exceeds what the R430 is capable of and matches the pattern above, then your card very likely has the R480 GPU.
Here are the steps to performing the name/GPU type mod:
- Find out what type of GPU your card has (it will be in the format of R4xx). If it does not say R480 and your card is a Radeon X800 GT, GTO, or GTO² card, if you like you may use one of the methods above to determine whether it is R480 or not. If it is R480 and is not being shown as such, you may want to use R480 as the GPU type. Otherwise, just use the same GPU type.
- If you are modifying your own bios, get a dump of the bios if you haven't already done so (this can be done with ATITool).
- Open the bios you are editing in RaBiT.
- Find the driver information file for the driver version you are currently using. The location of it will be in the main installer folder -> Driver folder -> 2KXP_INF folder. There will be two of these file types, one for Windows 2000 (C2_?????.inf) and one for Windows XP (CX_?????.inf). Open one of them.
- Search the file for the desired name and proper GPU type. You may also search for an entry with the same SubVendor ID as your current bios. The entries are formatted as shown in this picture:
- Enter the information in RaBiT from the entry in the file. The values that you want to change are Device ID, SubSystem ID, and possibly SubVendor ID (depending on whether you found a vendor-specific entry in the file or not for the card type you chose). The locations of the values to use from the entry are shown above.
- Save the modded bios with a different name.
- The modded bios is done.
After flashing the modded bios, the next time Windows starts up it will detect a new video card with the new name.
If you have any questions about any parts of the guides or find any mistakes or incorrect information in them, let me know.
ok i now flash my AGP ATIcard, to X850XT now my clock is 520 core & 540 mem.
