Configuring System BIOS

These settings cover different generations of equipment, and some motherboards offer more settings than others, so not all will be available in any one machine and sometimes you may have to apply a little creative thought to apply the wording used here to your situation.

As much as is possible for the way the computer is to be used, you should aim to disable unwanted onboard resources: serial / parallel / sound / modem / infrared / game port / USB so as to free resources and achieve a minor performance gain.

Upgrading System BIOS

Before configuring the existing system BIOS, check the motherboard manufacturers' web site for an updated version. If an update is available and it fixes worthwhile probelms then its probably worth installing

Standard CMOS Features

don't auto search for ATA/IDE primary slave and secondary master and slave, etcetera, devices that don't exist (system boots quicker)

Advanced BIOS Features

anti-virus protection / Virus Warning / TrendChipAway
enabled - gives some protection but slows system down
disabled - if dual booting with another operating system using a boot loader such as LILO it is easier to disable this else it complains each time you boot
set the first boot device to be the hard disk with the boot partition (probably HDD-0) (for security, and system boots quicker)
boot up floppy seek - disabled (performance)
Gate A20 Option - fast
prevent software from editing the BIOS, such-as virii:
'BIOS Guardian' or 'Flash BIOS Protection'
- enabled
- disabled (when you need to allow software to write to BIOS, e.g. when flashing BIOS. a modern BIOS may warn you at startup that this is disabled)
video BIOS shadow / video ROM BIOS shadow - enabled (should always be enabled. for increased video performance but is virtually unused with a 32bit operating system)
XXXXX-XXXXX Shadow - for DOS, no longer necessary under Windows 98SE, Windows 2000 and onwards

Advanced Chipset Features

DRAM refresh rate - match this with the speed of DRAM (i.e. 80ns, 70ns, 60ns)
DRAM wait state
SDRAM RAS to CAS delay - lower is faster
SDRAM RAS precharge time - lower is faster
SDRAM page closing policy - 'all banks' is faster than 'one bank'
RDRAM frequency: FSB ratio - auto (manually adjust the ratio between the front-side-bus and memory speed)
CPU fast string - enabled (optimises the performance of the Intel Pentium 4 when using RAMBUS)
video memory cache mode - USWC is faster than UC
SGP capability - higher is faster
high priority PCI mode - enabled
SDRAM data driving mode
normal
strong - higher memory performance, disables error correction
memory early/delay write - auto
DRAM Timing By SPD
enabled (automatically judge settings below using SPD)
disabled (configure settings below manually)

DRAM Clock - match to speed of RAM
SDRAM cycle time (tras,trc) / SDRAM Cycle Length / SDRAM CAS Latency - match this with the RAM's rating (i.e. 2, 3) - lower is faster
DIMM interleave setting - Bank Interleave - enable for increased performance/stability: "Each SDRAM DIMM consists of either 2 banks or 4 banks. 2-bank SDRAM DIMMs use 16Mbit SDRAM chips and are usually 32MB or less in size. 4-bank SDRAM DIMMs, on the other hand, usually use 64Mbit SDRAM chips though the SDRAM density may be up to 256Mbit per chip. All SDRAM DIMMs of at least 64MB in size or greater are 4-banked in nature. If you are using a single 2-bank SDRAM DIMM, set this feature to 2-Bank. But if you are using two 2-bank SDRAM DIMMs, you can use the 4-Bank option as well. With 4-bank SDRAM DIMMs, you can use either interleave options. Naturally, 4-bank interleave is better than 2-bank interleave so if possible, set it to 4-Bank. Use 2-Bank only if you are using a single 2-bank SDRAM DIMM. Note, however, that Award (now part of Phoenix Technologies) recommends that SDRAM bank interleaving be disabled if 16Mbit SDRAM DIMMs are used. This is because early 16Mbit SDRAM DIMMs used to have stability problems with bank interleaving. All SDRAM modules can now use bank interleaving without stability problems."

RDRAM frequency: FSB ratio (ratio between FSB and RAM speed)
CPU fast string - enabled
system BIOS cachable
enabled (for increased performance, but poorly written programs that write to the memory area used for the caching will crash)
disabled (to guard against USB problems, especially with VIA chipsets)
video BIOS cachable - enabled (for increased video performance. but be careful, disable if system crashes/hangs - poorly written programs that write to the memory area used for the caching will crash)
video RAM cachable - enabled (for increased video performance. but be careful, disable if system crashes/hangs - poorly written programs that write to the memory area used for the caching will crash)
CPU level 1 cache - enabled
CPU level 2 cache - enabled
CPU level 2 cache ECC check - disable (1% performance gain)
system performance - optimal (fast memory timing)
PCI latency timer - only change so as to remedy problems with sound
SCSI BIOS - disabled (unless required) - speeds bootup time
primary VGA BIOS - PCI or AGP (dependent upon the video device being used, or which to boot using if have 2)
reserve IRQs only for ISA cards that specifically require them
spread spectrum control - disabled (for increased performance)
PCI to DRAM prefetch - enabled - slight performance gain
spread spectrum control
enabled - for meeting the specification for CE acceptance test - noticeable deterioration in performance
disabled -
graphics aperture size / AGP aperture size - 32MB is fine as its mostly ignored
AGP Capability - set to whatever your motherboard and AGP adaptor support. makes a huge impact on graphics performance
AGP fast write - enabled (significant increase in video performance if video card supports it, otherwise it can crash the system so disable it if this happens)
AGP drive strength P ctrl ("at best, is designed for experimentation freaks - but not for anything else!")
High priority PCI mode - enabled
OnChip USB - disabled (if don't use USB) / enabled (if use USB)
OnChip USB 2 - disabled (if don't use USB) / enabled (if use USB)
USB Keyboard Support
disabled (if don't have USB keyboard)
enabled (if have USB keyboard)
OnChip Sound - enabled (unless you don't need sound or have a seperate sound card)
OnChip Modem - disabled (unless you need it)

Integrated Peripherals

onboard Serial Port 1
disabled, unless required
onboard Serial Port 2
disabled, unless required
onboard parallel mode:
disabled, unless required, whereby, either:
ECP for printer or scanner (version 1.9, if problematic use 1.7)
EPP for parallel port peripheral or if have DMA clash when using ECP
OnBoard Legacy Audio - disabled (unless you need it for games) (this will disable the game por

PnP/PCI Configuration

Plug'n'Play OS installed
yes - for Plug'n'Play operating systems (Windows 95,98,Me,2k,XP)
no - for non Plug'n'Play operating systems (Windows NT4) or if need to manually configure IRQs to avoid sharing
Assign IRQ For VGA - disabled (but enable if your high-end video card needs an IRQ (see video card documentation)
Assign IRQ For USB
disabled (if don't use USB devices)
enabled (if use USB devices)

Power Management Setup

ACPI / APM - enabled
(disabled with Windows 98 and VIA chipsets to guard against USB problems)
For Windows 2000 to use ACPI you need to turn it on before installing the operating system. Don't set the suspend and standby values, leave that to the operating system to manage.
Modem Use IRQ - NA (unless required)
State After Power Failure - off for a workstation; on for a server

Frequency/Voltage Control

spread spectrum control - disabled (for increased performance)

Miscellaneous

For Pentium 4 CPUs with hyperthreading under Windows 2000, turn it off