User manual ABIT SG-81

[. . . ] (SG-80, SG-81) Intel Pentium 4 System Board Socket 775 User's Manual SG-80 Series Rev. 1. 00 Copyright and Warranty Notice The information in this document is subject to change without notice and does not represent a commitment on part of the vendor, who assumes no liability or responsibility for any errors that may appear in this manual. No warranty or representation, either expressed or implied, is made with respect to the quality, accuracy or fitness for any particular part of this document. In no event shall the manufacturer be liable for direct, indirect, special, incidental or consequential damages arising from any defect or error in this manual or product. [. . . ] Do not change the values in this field unless you change specifications of the installed DRAM or the installed CPU. DRAM CAS Latency: This item controls the timing delay (in clock cycles) before the DRAM starts a read command after receiving it. RAS Active Time (tRAS): This item allows you to set the amount of time a RAS can be kept open for multiple accesses. RAS Precharge Time (tRP): This is the duration of the time interval during which the Row Address Strobe signal to a DRAM is held low during normal Read and Write Cycles. This is the minimum interval between completing one read or write and starting another from the same (non-page mode) DRAM. Techniques such as memory interleaving, or use of Page Mode DRAM are often used to avoid this delay. Some chipsets require this parameter in order to set up the memory configuration properly. The RAS Precharge value is typically about the same as the RAM Access (data read/write) time. User's Manual 3-12 RAS to CAS Delay (tRCD): Chapter 3 This is the amount of time a CAS is performed after a RAS. The lower the better, but some DRAM does not support low figures. Press <Esc> to return to the Advanced Chipset Features page. AGP & P2P Bridge Control Scroll to this item and press <Enter> to view the following screen: AGP Aperture Size This setting controls just how much system RAM can be allocated to AGP for video purposes. The aperture is a portion of the PCI memory address range dedicated to graphics memory address space. Host cycles that hit the aperture range are forwarded to the AGP without any translation. Graphic Window WR Combin (Enabled) Use this item to enable or disable CPU support for WR Combin feature. AGP Fast Write Support (Disabled) This item lets you enable or disable the caching of display data for the video memory of the processor. SG-80 Series BIOS Setup 3-13 AGP Data Rate (Auto) This item allows users to set the AGP Data Rate by, Auto, 1X, 2X, 4X, or 8X, depending on what speed the AGP card supports. Press <Esc> to return to the Advanced Chipset Features page. OnChip AGP Control Scroll to this item and press <Enter> to view the following screen: VGA Share Memory Size (32M) This item allows you to select the shared memory size for VGA usage. Press <Esc> to return to the Advanced Chipset Features screen. System BIOS Cacheable (Disabled) This feature is only valid when the system BIOS is shadowed. It enables or disables the caching of the system BIOS ROM at F0000h-FFFFFh via the L2 cache. This greatly speeds up accesses to the system BIOS. Video RAM Cacheable (Disabled) This feature enables or disables the caching of the video RAM at A0000h-AFFFFh via the L2 cache. User's Manual 3-14 Chapter 3 3. 2. 4. Integrated Peripherals These options display items that define the operation of peripheral components on the system's input/output ports. OnChip IDE Device Scroll to this item and press <Enter> to view the following screen: SG-80 Series BIOS Setup 3-15 Internal PCI/IDE (Both) Use these items to enable or disable the internal PCI IDE channels that are integrated on the mainboard. IDE DMA Transfer Access (Enabled) This item allows you to enabled the transfer access of the IDE DMA. IDE Burst Mode (Enabled) This option, when enabled will instruct the system to send every write transaction to the write buffer. [. . . ] Please understand that we are selling through distribution channels and don't have the resources to serve every end-user. However, we will try to do our best to help every customer. Please also remember that for many of our technical support team English is a second language, you will have a better chance of getting a helpful answer if your question can be understood in the first place. Be sure to use very, simple, concise language that clearly states the problem, avoid rambling or flowery language and always list your system components. [. . . ]