How To: Overclock an X1800 or X1900 series card using ATITool. - Overclock.net

*Chozart* · 09-14-06

ATITool is a very useful tool when overclocking any ATI graphics card (with some exceptions), and even some nVidia cards. However, it has some quirks that will be addressed in this FAQ.

High-End ATI cards have 2D/3D clocks that are automatically switched by ATI's drivers when an application enters 3D mode. Thus, in 2D mode the cards run at lower clock speeds and voltages to conserve power and to lower temperatures. When 3D mode is enabled, clock speeds and voltages are increased to achieve the full potential power of the cards. This functionality exists currently on the X1800 and X1900 series of cards.

The problem is that ATITool is not compatible with this clock switching functionality, and thus this functionality needs to be disabled to allow over clocking with ATITool. In the newest version, 0.25 beta 15, ATITool automatically switches to 3D mode. However, this version is very buggy in my opinion, and I went back to using version 0.25 beta 14. This FAQ is based on that version of ATITool.

To set up your X1800 or X1900 series card in ATITool, please follow these guidelines:

Start ATITool. You will get a message dealing with the 2D/3D clock switch. In this message, ATITool asks you if you want to terminate the ATI2EVXX.EXE process that controls the clock switch. Answer 'Yes' to this message, and ATITool will start.
To your surprise, you will now see lower clock speeds than you expected. The clock speeds reported are obviously the 2D clock speeds. To fix this problem, first we need to make a new profile for the 3D clock speeds. Click 'New' at the top of the main ATITool window and give the new profile a name.
The next step is first to enter the correct voltages. If this is not done, increasing the clock speed will lead to instabilities. Click 'Settings' on the bottom right of the main ATITool window. You will now be presented with a window where you can control a host of options. For those who use Crossfire, you will need to do the following steps twice, once for each device in the 'Use Device' drop down list. For now, I will assume you have a single card. From the drop down list on the top, select 'Voltage Control'

You will be presented with a screen where you can set your desired voltages. In this case, we're mainly concerned with the core voltage (VGPU), since the memory voltages (MVDDC and MVDDQ) and the additional core voltage (VDDCI) for X1900 cards are the same in 2D and 3D mode. Move the top slider to 1.375V if you have an X1800XT card, and to 1.425V if you have an X1900XT or X1900XTX card. I am in the process to find the correct voltages for the other X1800 and X1900 series cards, and will update this FAQ once I find them.

After you set the voltage using the slider, click 'Save' on the bottom of this window and select the profile you just created. The click 'Back' to return to the main window.
Now, select the default 3D clock speeds for your card. For the X1800XT, the correct clock speeds are Core: 625, Memory: 750; for the X1900XT, Core: 625, Memory: 725, and for the X1900XTX, Core: 650, Memory: 775. (again, I will update for the other cards in these series). After entering the clock speeds, or using the sliders to select them, don't forget to click on 'Set Clock'

You'll likely see a small discrepancy after ATITool sets the clock speeds.
Select your new profile from the drop down list on the top and click 'Save' to save your new clock settings. In the drop down list, you will see the clock speeds changing also.
Finally, you want this new profile to load in ATITool each time you start it up. Click 'Settings' again, and select 'Startup' from the drop down menu. Here you can select the profile you want ATITool to use when you start it, and also you can choose to start ATITool at Windows startup. Personally, I would not recommend the latter, since your card will be running at 3D speeds at any time, even when using Overclock.net. This will result in higher power consumption.