Chapter 5: BIOS as Additional Performance Reserve

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Overview

The efficiency of computer-hardware operation strongly depends on the Basic Input/Output System (BIOS). BIOS code is stored in nonvolatile RAM and is an integral part of the architecture of any contemporary PC. Newer versions of this code can eliminate bugs related to controlling the existing hardware, as well as extend the range of components. Additionally, improved BIOS code often enhances PC functionality and improves its performance.

The contemporary PC comprises a large number of highly integrated semiconductor chips. They are distributed among various components that form the foundation of the entire system. Components and their elements are known as computer hardware, controlled by system and application software.

In multilayer software organization, a part of the system programs, the BIOS, is stored in Read-Only Memory (ROM).

The BIOS is an integral part of any contemporary PC. It implements the simplest and most universal functions required to control standard peripheral devices (input/output organization), relieving the operating system from accounting for the specific features and details of individual peripheral devices. The BIOS "hides" architectural features of specific PC models and ensures software independence on peripheral devices. The BIOS contains standard device drivers, test programs, and a bootstrap loader. The bootstrap loader is system-independent; it can work with any OS designed to run on the IBM PC architecture, which serves as the basis for contemporary PCs.

BIOS functions fall into the following categories:

• Power-On Self-Test (POST) routine — Initializes and tests computer hardware

• BIOS Setup — Configures and fine-tunes the entire computer system

• Bootstrap loader — Loads the operating system

• BIOS Hardware Interrupts — Performs maintenance and controls interrupts

• ROM BIOS Services — Processes software calls to system devices

On contemporary PCs, BIOS code resides in flash memory — on a Flash ROM chip. This allows PC users to modify or update BIOS versions using built-in computer hardware and software.

The motherboard BIOS is responsible for correct operation of the entire computer system. Overall system stability and performance strongly depend on the quality and efficiency of BIOS code. This is especially true for overclocked modes. Motherboard manufacturers, in cooperation with BIOS developers, make significant efforts to improve BIOS code. As a result, improved BIOS versions constantly appear, both for new products and for existing models of motherboards.

Improved versions of BIOS software code are intended for the newest components. They take into account the advanced architecture of these components, as well as improvements related to installation and operation. New BIOS versions often compensate for the drawbacks of earlier models.

Because flash-memory chips store BIOS code, PC users can periodically update the system BIOS. Some computers equipped with older motherboards might experience problems when working with contemporary components under control of contemporary operating systems such as the Windows 9x/ME or Windows 2000/XP.

In this situation, it is expedient to update the BIOS version. Most motherboard manufacturers, including Abit, Asus, and Chaintech, strongly recommend that PC users update older BIOS versions. This deserves consideration, particularly if you are using the newest models of processors. A BIOS update may be helpful if you are using Intel Pentium III with a motherboard whose specification states the product can be used with Intel Pentium II, but provides no information about Intel Pentium III support. In many cases, the BIOS must be updated when using Intel Pentium III with the Coppermine core. The same recommendation applies to Intel Pentium 4 processors when migrating to models that support hyperthreading technology.

Some motherboards have hidden potential. A BIOS upgrade can help reveal these hidden capabilities and make them available. For example, it is possible to widen the range of supported system-bus frequencies and core voltages for many motherboards. In most cases, this allows the newest processor models to be used with older motherboards.

The Asus P3B-FB motherboard, which was once widely known and popular, serves as a good example. Versions manufactured before the release of Intel Pentium III with the Coppermine core can work with processors of this type after a BIOS upgrade.

Another example that demonstrates the implementation of hidden capabilities of motherboard architectures is the use of hyperthreading technology after a BIOS upgrade. The manufacturer itself recommends this approach: Intel provided all the necessary information on the Intel Pentium 4 processors and its Hyper-Threading technology to motherboard manufacturers, which enabled them to develop code files. As a rule, motherboard manufacturers provide information required for a BIOS upgrade to their distributors; they also place it on their Web sites so that it is available to the PC user community. Most manufacturers even offer several BIOS versions on their Web sites. Usually, these sites also provide special utilities for upgrading the BIOS, as well as documentation explaining the functionality that will become available after a BIOS upgrade.

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