ATI Catalyst Tweak Guide

[Page 10] Advanced Tweaking (Pt 2)


This section of ATT is quite comprehensive and contains a range of Standard and Advanced Tweaks, some of which we will cover here, others which require you to experiment and test depending on your situation. Unfortunately there simply isn't enough room to cover them all in this guide, I'm also not familiar with all of the settings, and finally most of them are not particularly useful in normal circumstances. However once again it's great that ATI Tray Tools provides us with a means of easily accessing them if required.

Standard Tweaks

Override Pixel/Vertex Shader Version: These two options allow you to set a Shader level lower than your current maximum supported shader version. This can be useful in some games which don't allow you to alter the shader level within the game itself, but adjust their graphics for different shader levels. For example, if you set a card which has 2.0 shader support to override this and force 1.1 shaders, it will run some games more quickly at the cost of some image quality loss. However note that certain games will not run on lower shaders - they require a particular level of shader as a minimum - or they will display visual glitches if forced to use lower level shaders. You may even be booted from some online games by using a lower shader level, as PunkBuster may detect this as a cheat. Note, you should also always tick the 'Optimize Pixel Shader Code' box for maximum shader performance regardless of the version you're using.

Geometry Instancing: This is covered in the Catalyst Control Center section of the guide, and should be enabled in most cases.

Force Mip-Map Filter: Enabling this option improves the quality of textures in some games, although ideally you should use the regular Mipmap Detail Level setting to control Mipmap quality.

Z Compression: Controls the compression of the information held in the Z-Buffer. By enabling higher levels of compression (such as 'High'), you will see a performance improvement, but you may also see graphical anomalies. Default is the normal and recommended option, as it already provides some level of compression without image quality loss.

Fast Z Clear Enable: If enabled this option increases performance by clearing the Z-Buffer more quickly. As such it should always be enabled (ticked). Only untick this option if you experience Z-Buffer-related problems and want to experiment to see if this is the cause of it. Disabling Fast Z Clear will reduce performance noticeably.

Z Mask: Z Mask when enabled uses your graphics card hardware to prevent the Z-Buffer from being filled with unnecessary information. Strangely, many users report faster performance with Z Mask disabled (unticked), as well as less likelihood of graphical anomalies, so I recommend unticking this option to begin with to see if it works for you.

Z Top Disable: I am unclear what this option does, but it is unticked by default.

VPU Recover: Same as the ATI setting of the same name, see Catalyst Control Center section of this guide. Recommened that it be disabled (unticked).

Disable DMA Copy: I am unclear what this option does, but it is unticked by default.

Disable Block Write: Using Block Write should result in faster writing of graphics information to the VRAM, but some people report performance issues with it enabled (unticked) as it may be queing information instead of writing it immediately. So if you want to experiment, untick this option, try your favorite games or graphics benchmark and see if performance has improved or decreased for you. I recommend leaving it ticked by default.

WMV Acceleration: This setting is available in the regular CCC. It should be enabled to provide hardware accelerated Windows Media Video playback.

Advanced Registry Tweaks

There are 7 sections to this part of ATT, and there are a wide range of options here. Just like the Standard Tweaks above, these settings are held in the Registry, and ATT simply reads them from there. If they are currently enabled, the box next to the value's name will show a tick. If they are disabled, the box will be blank. If there is no set value (e.g. the registry item doesn't exist in your registry), then the box will be blocked in. I provide details of all the known and/or important settings below, and if you have good working knowledge of what the others do (or corrections to the list below), please Email Me.

Important: Altering some of these settings may be detected as a cheat by online anti-cheat software such as PunkBuster. Please keep track of the changes you make here, and keep them in mind if you are continually kicked from a game server with a PB warning.

Advanced Direct3D Tweaks

As the title suggests, these tweaks only work in Direct3D games, and have no impact on OpenGL games. Fortunately most games are Direct3D; there are very few OpenGL games (Doom/Quake-based games are OpenGL).

Fog Options: There are a range of Fog-related options here, including the option to enable hardware support for Table Fog, W Fog, Z Fog, Vertex Fog and Discrete Fog. For all intents and purposes you shouldn't need to manually enable/disable these, as your graphics card hardware should automatically provide support for the appropriate fog rendering method a game requires. However if the fog effects in a particular game look odd or incorrect - especially older games - I suggest firstly making sure Table Fog (Pixel Fog) support is enabled, then W Fog, and finally enable the other options if you still have problems. These options are really only for troubleshooting purposes.

Export W Buffer: This option enables W Buffer support for games which use it. The W Buffer is an alternate depth rendering technique to the Z Buffer. You should tick this, however ticking this option doesn't force-enable the W Buffer on recent ATI cards because they may not have hardware support for W Buffer usage in the first place.

Fast Color Clear: Enabling this should result in improved performance without noticeable image quality drop, as color information is cleared more quickly from the frame buffer. However it should already be enabled by default in the hardware, even if not indicated here.

VoltxEnable: This option controls support for Volumetric Textures, which should be enabled.

Color Compression: Enabling this should result in improved performance without noticeable image quality drop by compressing color information and hence allowing more information to fit into Video RAM. This should already be enabled by default in your hardware, even if it's not indicated here.

Export MipMap Cube Maps: Enabling this should provide support for Mipmap textures on Cube Maps. Cube Maps are a trick to show reflections of surroundings on static reflective object surfaces with minimal performance cost, and Mipmaps are a series of pre-scaled textures used to improve rendering performance as an object recedes into the distance. Once again, this should already be on by default, but you can tick it to make sure it's enabled.

Export Signed Vol Textures: I have no idea what this setting does. I assume it allows support for a particular Volumetric Texture type/method.

Line AA Enable: This option refers to Line Antialiasing - antialiasing which only works on lines, not the outlines of shaded or filled objects (e.g. powerlines in a 3D game). Enable this and test in a game to see if thin standalone lines become less jagged at the cost of some performance.

Enable Raster Guardband: This option controls Hardware T&L Guard Band Clipping, which is an optimization technique to improve video performance by only clipping (removing) certain portions of the 3D world, and this in turn saves CPU time. It should be enabled by default, but enable it here anyway. Only disable if you notice a reduction in performance or you see visual glitches.

Allow Macro Volume Textures: I have no idea what this setting does. I assume it allows support for a particular Volumetric Texture type/method.

Force Compressed Stencil Buffer: The Stencil Buffer is shared with the Z Buffer and most often controls effects like shadows in games. Ticking this option forces the stencil buffer data to be compressed, which may improve (or hurt) performance depending on the game; you should experiment to see which works best for you.

Constant Compare Enabled: I have no idea what this setting does.

Support for Non power of two size textures: This option enables support for non-standard texture sizes, and should be enabled.

Support for Displacement Maps: Unlike Bump Maps which are a trick to simulate bumps, scratches and dents in objects, Displacement Maps allow objects to show actual depth characteristics, even when viewed from the side for example. This technique is used in recent games, so support for it should always be enabled.

Adaptive NPatch Support: N-Patch is an ATI-developed technology for making 3D surfaces more realistically curved, and is used by ATI's TruForm technology. However this requires support in games to function properly, and most games do not support TruForm or N-Patch.

Tiling Settings: These settings control support for various texture surface tiling methods. I recommend enabling them all, as they all should be supported by your graphics card and may be used in particular games to improve performance as necessary.

Advanced OGL Tweaks

As mentioned earlier, these tweaks only apply to OpenGL games, such as those based on the Doom/Quake engines.

Force Vertex Cache for Iris: I have no idea what this setting does.

DitherAlpha: If enabled, Alpha Textures - that is textures with transparent areas (like chain link fences) - will be dithered. This means the colors are blended more smoothly and hence should look better. Disabling this may resolve any visual glitches and may improve performance in OpenGL games, but will show more color banding (i.e. more noticeable color gradation).

Disable AGP Blit: Blitting is used primarily for 2D graphics and there should be no reason to disable or alter this option, unless perhaps you're having problems in a 2D game.

Disable FGL AGP: Not clear what this setting does, perhaps it's related to disabling the ATI FireGL graphics card series' AGP function.

Export OpenGL 2.0 Procedures: Should be enabled, as this provides support for OpenGL 2.0 functions. You should only disable this if an OpenGL game or application is not functioning properly.

CCC Mode Switch

Enable Merged 3D Mode (Emulate Control Center): This option is ticked by default to emulate the Catalyst Control Center settings. I recommend you leave this enabled, as most of the descriptions in this guide refer to CCC functions, and the old Control Panel is no longer being updated by ATI to include newer options/settings.

Compatibility Tweaks

These settings are very dangerous, and should only be altered if you know precisely which setting (and why) you want to disable. As the name of this section suggests, you would only want to disable these functions to ensure compatibility with a particular game or application, otherwise they are all best left at default and won't be covered individually here.

Display Tweaks

Once again, these settings are quite dangerous to alter and you must know what you're doing, and have a specific reason in mind, before altering them. The most common reason would be if your connected display is not being correctly detected, however you should try the troubleshooting methods built into main CCC/ATT Displays sections before resorting to altering these.

Multi Thread Support

Enable MT Support: If you have a multi-thread capable CPU, that is either a dual/multi core CPU, or a CPU with HyperThreading (virtual dual core) technology, you can enable this option for a potential performance improvement. You should leave the 'Minimum Working Threads' to 0 and set the 'Maximum Working Threads' to a value like 2 to start with. Play some recent 3D games and see if you get an actual improvement in performance, and also note if there is any additional instability caused. If it remains stable and you also notice a performance improvement, raise the Maximum value to 4, 6 or 8 for example and again experiment.

New AA and AF Methods

Here you can disable support for Adaptive Antialiasing and/or High Quality Anisotropic Filtering, as well as enabling other Antialiasing and Anisotropic Filtering modes, such as EATM which is covered in more detail here. In general you should leave these settings alone unless you know exactly what you're doing or you're willing to experiment.

Video Tweaks

These settings all relate to hardware acceleration support for particular video formats (not 3D games). By default you should have DXVA_WMA (Windows Media Acceleration) enabled. However apparently enabling acceleration for other formats can destabilize your system, so please be wary.


This section of ATT allows you to assign hotkeys which you can use to quickly access particular ATT functions. This is fairly self-explanatory, and it is up to you whether you wish to enable hotkeys or not, depending on how often you access particular functions in ATT. Hotkeys must be enabled (ticked) here for your hotkeys to work while ATT is running.


This section of ATT shows the various Plugins which have loaded into memory along with ATT to enable particular functionality - such as those used in FlashOSD (See below). You can enable, disable or configure these plugins as required.


This section of ATT is essentially the same as the Displays options covered in the CCC section of this guide, and won't be covered in detail here. If you don't have any issues with your display(s) setup you don't need to alter these settings.

Refresh Lock

As discussed on page 4, it is recommended that you select the highest refresh rate possible at your chosen resolution(s) to minimize eye strain. You can do this using the Refresh Rate Fix methods mentioned on page 4, or you can use this section of ATT to both create a new custom resolution and/or set a new refresh rate for a specific resolution. Once again note that you must not try to force a higher refresh rate than your monitor can support at your chosen resolution, as this will cause an 'Out of Frequeny' black screen and potential damage to your display.


This section of ATT is essentially much the same as the Rotation settings in the CCC - see that section of this guide for appropriate setting descriptions.

Video & Colors

This section of ATT is essentially much the same as the Video and Color settings in the CCC - see that section of this guide for appropriate setting descriptions.

Tools & Options

The General Options for ATT are covered at the start of the previous page. However there are some additional functions here you may find useful:

Dump Video BIOS: If you want to save a copy of your current video card BIOS, select 'Dump Video BIOS' and a BIOS Dump.bin file of your current BIOS will be saved to your chosen location. This can be useful if you're upgrading your video BIOS and want to keep a backup copy of the original version, or if you want to alter the BIOS in a BIOS editor.

Save Desktop Icon Positions: Basically this option allows you to save your current desktop icon positions, and if at any time your icons get moved/messed around (e.g. after a driver update), you can select 'Restore Desktop Icon Positions' to do exactly that. Note that this is not a tweak specific to ATT or ATI graphics cards - I cover how to implement this tweak on any system in the TweakGuides Tweaking Companion.

On Screen Display: Another very handy feature of ATT is the ability to show useful information on screen at any time while a game is running, such as your current framerate, or information about your system temperatures. To enable the On Screen Display (OSD) function, under the OSD tab tick the 'Enable OnScreen Display' box. If you don't want the OSD to appear in overlays such as Videos, click the 'Disable OSD in overlays' box. You can then customize where the display text appears and how it behaves. Note that you can enable/disable the OSD for particular games using the Game Profiles (see previous page), and you can also assign hotkeys to OSD functions (See Hotkeys section), so that for example you can toggle the display of the OSD at any time rather than having it on all the time.

FlashOSD: Under the FlashOSD tab, you can set up additional display items for the OSD, such as your GPU speed, System Memory used and Motherboard temps. You can select whether this additional display is brought up automatically at regular intervals by selecting the 'Auto Flash' option; whether it is constantly shown by selecting 'Show All Time'; or whether it is only triggered manually using a hotkey by selecting 'Manual'. I recommend assigning a hotkey to this function and selecting Manual, as the other options can be annoying or can interrupt game performance. Note that for additional information like Motherboard temps, you will need to enable a relevant FlashOSD Plugin and then click the Configure button.

That concludes our look at ATI Tray Tools, which is clearly a very detailed and handy utility, and can serve ATI users quite well in replacing or supplementing the existing Catalyst Control Center. Remember that some of the settings and descriptions may alter slightly with various revisions of ATT. If you find that there are any major settings or functions missing, or indeed inaccuracies in the descriptions above, please Email Me. However please keep in mind that I can't provide tech support. Finally, I recommend that if you find ATI Tray Tools useful, that you consider giving the tool's creator Ray Adams a donation to show your support. You can do this by going to the About item in ATT's main menu. He is maintaining ATI Tray Tools to the benefit of thousands of users with his own resources and no help from ATI, so I think he deserves some support if you find the tool useful.

The next section of this guide covers the basics of video card overclocking.