How to Setup BIOS

ROM BIOS from, say, Award, has an embedded setup program, which allows you to change the basic configuration of the system. This information is permanently stored in CMOS RAM, so its contents will not be lost after turning the PC off.

You can enter the Setup mode by pressing a certain key or combination of keys when you restart or reboot the computer. Usually the key is used for this purpose.

The system configuration is modified by setting the values of the appropriate parameters in BIOS Setup and then saving them in CMOS RAM. This procedure is known as BIOS Setup. Most often, the overall performance of the entire computer system depends on the BIOS settings.

In many cases, changing parameters in BIOS Setup provides a real possibility of significant improvement of the computer performance. This is particularly true for the parameters that deal with memory. Generally, default settings ensure the stable operation of the entire system.

However, these settings do not guarantee maximum performance. To achieve this, you'll need to try to select settings at which the computer will function at maximum performance and at the same time remain stable. In order to attain maximum performance by means of BIOS Setup.

It is necessary to experiment with the settings that define time delays when accessing RAM (BIOS Memory Timing menu), internal, and/or external cache memory. It's also advisable to give some attention to the parameters that determine the modes of the video adapter and hard drive.

Managing RAM

Choosing the parameters, you can almost always assume that the less delay, the better. At the same time, settings that are too low may lead to the unreliable operation of the memory, and thus make the whole system unstable.

In such a case, simply load the default settings (BIOS Setup Defaults menu) and the system will return to its original state. By changing the parameters associated with memory time delays in BIOS Setup, it is impossible to harm the computer.

If the system is not working correctly, or if it completely refuses to work, you can simply return to the original settings. A more detailed explanation of each of the parameters can be found in the manual for the motherboard, or in the appropriate technical literature. Here, you'll find a few examples of how to adjust them with the aim of increasing the RAM operating frequency.

Most frequently, all of the necessary parameters that control the work of the RAM are found in the BIOS Setup menu called Advanced Chipset Setup. The items on this menu are listed below.

You can usually change the values using <+> and <> or and keys. Enabled/Disabled refers to enabling or disabling the corresponding option.

  • Auto Configuration - All parameters will be set automatically. In order to be able to set the parameters manually, it is recommended that you disable this option. If this option is enabled, most parameters will be set automatically.

  • DRAM Read Timing - The number of cycles while accessing the memory. This parameter can take on the values x111, x222, x333, and x444. The less the number of cycles, the better. To achieve maximum performance, you must assign this parameter the lowest possible value.

However, make sure that the system is stable at the modified settings. The possible (and recommended) values are: EDO RAM — x222 and x333, FPM RAM — x333 and x444, SDRAM — x111 and x222.

  • DRAM Write Timing - It is recommended that you change this parameter in a way similar to the one used to modify the previous one.

  • RAS to CAS Delay - Try to set the lowest possible value for this parameter. Notice, however, that not every RAM module will be able to work with the lowest setting. Because of this, it is recommended to test your system after changing this setting.

  • DRAM Leadoff Timing - The value of this parameter depends not only on the type of the memory installed in your system, but also on the chipset at the motherboard. For read operations, Intel Triton FX chipset normally does not allow you to set DRAM timing cycles less than 7-x-x-x, while TX or HX chipsets require that this value be no less than 5-x-x-x.

For write operations, these parameters should be set to the values no less than 5-x-x-x (FX) and 4-x-x-x (TX and HX). At a value of 5, the system will be able to work if using 50 nsec EDO RAM or 10 nsec SDRAM. As always, it's worth trying to set the lowest possible value.

  • Turbo Lead Leadoff

  • Turbo Read Pipelining

  • Speculative Lead Off - You should try to enable these parameters, and then test the system's usability and performance. Certain types of RAM can produce a significant growth in performance if these parameters are turned on.

Cache Memory

The parameters that control the work of the cache memory are generally found in the BIOS Setup menu under BIOS Features Setup, the items in which are explained in more detail below. Usually you can modify the values using the <+> and <> or the and keys. Enabled/Disabled will enable or disable the option.

  • CPU Internal Cache/CPU External Cache - Internal/external CPU cache. This parameter allows the external/internal processor cache to work (or disables it). Disabling CPU Internal Cache/CPU External Cache will significantly slow down the whole system. However, this may be necessary if you are using any legacy hardware or software.

  • CPU L 1 Cache /CPU L 2 Cache - The processor cache of the first/second level. This parameter enables or disables usage of the first/second level CPU cache for the following processors: Pentium Pro, Pentium II, Pentium III, Celeron, AMD-K6-III, and so on. Disabling this option will slow down your system significantly. However, this may be necessary if you are using legacy adapters or legacy software.

  • CPU L 2 Cache ECC Checking - Uses ECC for the 2nd level cache memory. This parameter enables or disables the level 2 cache memory ECC for those processors built on the architecture using it.

Video Subsystem and Hard Drive

The parameters that control the functioning of the video subsystem, the hard drive, and the system BIOS are usually located in the BIOS Setup menu under BIOS Features Setup and Chipset Features Setup, whose items are described below. Usually you can modify the values using the <+> and < > or the and keys. Enabled/Disabled will enable or disable the option.

  • Video BIOS Shadow - A "shadow" copy of the video ROM. This parameter enables or disables creation of a „shadow” copy of the video BIOS in the RAM. When this setting is enabled, the contents of video BIOS will be copied into the RAM, and RAM will actually be used when formally accessing video BIOS. This allows a gain in performance, because working with RAM is obviously much faster than working with RAM.

  • Video BIOS Cacheable - This parameter enables or disables caching the video BIOS. Caching increases the speed of the video output.

  • System BIOS Shadow - This parameter enables or disables creation of a copy of the System BIOS in the RAM. When enabled, a copy of the system BIOS will be created in RAM, and all actual work will be done using this copy (while formally working with the system BIOS). The performance increase is due to the fact that RAM access is much faster than ROM access.

  • System BIOS cacheable - This parameter enables or disables caching the system BIOS. Caching increases the speed at which the system BIOS commands are executed.

  • AGB Aperture Size (MB) - This parameter specifies the size of RAM allocated to AGP video adapters. The parameter ranges from 4 to 256 MB. Memory is allocated dynamically, within the limits set by the values specified. The remaining part of the allocated memory can be used by the operating system.

  • AGP/CLK - This parameter sets the AGP clock frequency, which depends on the divider value and operative frequence of the CPU bus (FSB). When setting this parameter, you'll have two options: 1 (1/1, i.e., AGP clock frequency is the same as CPU clock) or 2/3 (i. e., AGP is at 2/3 of the CPU external clock).

  • IDE HDD Block Mode - Enabling this option will set a block data transfer mode for the hard drive, which will transfer data in blocks. This increases the speed of data exchange and, accordingly, boosts the performance of the disk subsystem.