For optimal performance, please ensure one (1) or more empty expansion slots separates each AMD Radeon™ HD 6990 graphics card in a dual mode AMD CrossFireX™ technology configuration.
The AMD Radeon™ HD 6990 graphics card features dual-BIOS capabilities. This feature is controlled by the Unlocking Switch, which toggles between the factory-supported Performance BIOS of 375W (BIOS1), and an Extreme Performance BIOS (BIOS2) that can potentially unlock higher clock speeds and up to 450W of mind-blowing performance!
Do not use the 450W setting unless you are familiar with overclocking and are using high-quality system components to ensure maximum system stability. If you encounter system instability or other unexpected system performance while using the 450W setting, return the graphics card to the factory-supported 375W setting, as your system may not be properly equipped to handle the increased demands of the 450W setting.
The following procedure describes how to switch between BIOS settings using the Unlocking Switch on your AMD Radeon™ HD 6990 graphics card.
- Locate the yellow caution sticker adjacent to the AMD CrossFireX™ connector on your AMD Radeon™ HD 6990 graphics card. This sticker covers the Unlocking Switch and must be removed to access and change dual-BIOS switch positions.
- WARNING: Before proceeding, thoroughly review the documentation for your AMD Radeon™ HD 6990 graphics card and assure that your computer meets all minimum system requirements.
- Remove the sticker and set the Unlocking Switch to the desired setting:
- Position 1 — 450W Extreme Performance BIOS (BIOS2).
- Position 2 (shipping position) — 375W factory-supported Performance BIOS (BIOS1).
WARNING: AMD graphics cards are intended to be operated only within their associated specifications and factory settings. Operating your AMD graphics card outside of specification or in excess of factory settings, including but not limited to overclocking, may damage your graphics card and/or lead to other problems, including but not limited to, damage to your system components (including your motherboard and components thereon (e.g. memory)); system instabilities (e.g. data loss and corrupted images); shortened graphics card, system component and/or system life; and in extreme cases, total system failure. AMD does not provide support or service for issues or damages related to use of an AMD graphics card outside of specifications or in excess of factory settings. You may also not receive support or service from your system manufacturer.
DAMAGES CAUSED BY USE OF YOUR AMD GRAPHICS PROCESSOR OUTSIDE OF SPECIFICATION OR IN EXCESS OF FACTORY SETTINGS ARE NOT COVERED UNDER YOUR AMD PRODUCT WARRANTY AND MAY NOT BE COVERED BY YOUR SYSTEM MANUFACTURER’S WARRANTY.