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ATI & NVIDIA Video Card Tweak Guide

By Ryan "Speedy" Wissman September 16, 2002


As today's video cards become increasingly advanced, the sheer number of options and tweaks that go unseen to the average user seems to increase. Sometimes these remain unseen because ATI and NVIDIA will often neglect, or outright refuse, to make these tweaks available with their standard driver package. While many of these configurable items can be relatively benign, there are still a healthy number of extremely rewarding (we're talking extra performance and image quality here) options that can greatly enhance the visual quality and speed of modern ATI and NVIDIA video cards.

From a stability standpoint, it's always wise to have the latest WHQL (Windows Hardware Quality Lab) certified drivers for your video card's respective chipset. Both NVIDIA and ATI will release newer drivers for their graphics products on a regular basis, fixing issues found in previous drivers, integrating new features, and offering greater compatibility with games and hardware. Finally, while we are talking about getting the latest software, you should also have the latest version of Direct X, which can be downloaded via Microsoft's Windows Update.

BIOS Settings

One of the most widely overlooked areas of video card tweaking has nothing to do with the 3D card or the drivers, and is located deep within your motherboard's BIOS. These settings are universal, and will work with most major graphics chipsets regardless of make or model; that is, as long as they are AGP-based and have been made in the last few years.

Usually, the BIOS can be accessed by pressing the delete or F1 key during the boot process. If you've tried those two, and still can't get into your System BIOS, then check your motherboard user manual, or check the system while it boots. There will often be instructions right on the screen, as to which key to press.

BIOS Settings: Part 1

It is recommended that the following System BIOS settings be disabled, if possible:

1) VGA Palette Snoop: This is only used when the computer is in 256-color mode, and retains a list of colors (the palette) currently in use by the video card. You may also find this option under the title "PCI VGA Palette Snoop," in which case you'll still want to leave it disabled.

2) Video DAC Snoop: This should only be enabled as a last resort if you are experiencing problems with your video card such as weird colors or blank/blinking screens.

3) Video BIOS Shadowing: This allows for the BIOS to copy the BIOS of the video card to system RAM for faster access. While this sounds like it should be left on do not be fooled, today's systems will bypass the BIOS completely when accessing a video card so there is no need to waste precious memory.

BIOS Settings: Part 2

Enabling or changing the following options will lead you to the happy oasis we call high performance. Please do remember that if you start to experience odd visual anomalies you will want to undo any changes you may have made in the BIOS. As with any BIOS setting, the best procedure is to try them one at a time and make sure no issues crop up before moving to the next one.

1) AGP Master 1WS Write/Read: By default, the system is set wait two cycles before it will make a read/write transaction. Enabling 1 WS will allow the AGP card to wait only one cycle before a read or write transaction occurs, slightly increasing overall performance.

2) AGP Mode: As long as your mainboard and video card support it, you will always want to select the highest possible setting, either 2X, 4X, or 8X, the latter of which offers optimal performance. (However, at the time of this writing very few 8X AGP capable video cards and mainboards were available for purchase).

3) AGP Fast Write Control: This is by far one of the most beneficial, and overlooked video card tweak one can perform in the BIOS. You will need to make sure that your video card supports this feature as it can cause major problems if you try enabling this feature without the proper support. AGP Fast Writes can increase video speed roughly 1-5% and is supported by most recent video cards. Fast Writes allows the computer to send video-based calls directly to the video card, thereby bypassing the system's main memory system.

BIOS Settings: Part 3

The following BIOS choices have unique options that go into more depth, than simply enabled or disabled:

1) Video Memory Cache Mode: When selecting this option, you are usually presented with two options, UC (UnCacheable) and UCWC (UnCacheable Speculative Write-combining). Here, you will want to select UCWC as it will enable the write cache of your video card's memory which will offer a slight increase in overall performance.

2) AGP Aperture Size/Graphics Window Size: This is a numerical number which represents the amount of memory your video card is allowed to access over the AGP bus. You are given choices such as 32, 64, 128, 256-MB, and as a general rule you will want to select about 1/4 or less of your total available RAM. The default for this option is generally 64-MB, usually the size one will want to run.

  • Page 1 ATI & NVIDIA Video Card Tweak Guide
    Page 2 ATI Video Card Tweaks
    Page 3 ATI Direct3D and OpenGL Tweaks
    Page 4 Game, Overclocking, and Resolution Options
    Page 5 NVIDIA Video Card Tweaks
    Page 6 NVIDIA Direct3D Settings
    Page 7 NVIDIA OpenGL Settings & Overclocking
    Page 8 Rivatuner Tweaks
    Page 9 Rivatuner Direct3D Tweaks
    Page 10 Rivatuner OpenGL Tweaks

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