The BIOS is rich in features that may well improve your system's performance if you have previously left it untouched or at its default settings. Although the BIOS from various manufacturers may differ in layout, they generally provide the same features and settings. However, certain OEM motherboards do have a limited-feature BIOS designed to keep the customer from doing anything detrimental to the system.
Various manufacturers have various means to access the BIOS screen, but the most common version would be to hit either the Del key or the F2 key during boot-up. In a standard BIOS menu screen, the available options that we are interested in are: BIOS Features, Chipset Features, Power Management and PNP & PCI Configuration.
Please note that the following information is based on my Asus TX-97E motherboard which uses an Award BIOS. Other manufacturers' BIOS screen and layout may differ slightly or completely altogether, but I will try to make everything as general as possible. 36298ehp35tgl8v
Virus Warning: This feature was designed to prevent programs (mainly viruses) from modifying the boot sector of your hard drive. Enabling or disabling this feature would usually have no effect on your system unless you use a program that regularly modifies your boot sector, such as a boot manager program or you are doing an installation of Windows 95/98.
Internal/External Cache: These should be enabled for obvious reasons. hg298e6335tggl
Quick POST: Generally left enabled. If disabled, booting up would be slower as the system would perform a more thorough Power On Self Test.
Boot Sequence: Unless you commonly boot up from a floppy or CD-ROM, setting the boot sequence to C Only should allow you to start up a little faster.
Boot Up Floppy Seek: Generally left disabled. Saves you a little time during boot up.
IDE HDD Block Mode Sectors: Determines the number of sectors that a hard drive can transfer per interrupt request. Usually leave it at the maximum value supported by your harddisk.
PCI/VGA Palette Snoop: Generally disabled unless you experience palette colour problems with your video card/MPEG card/etc.
Video ROM BIOS Shadow: Generally left disabled. The basic concept of shadowing is to copy the video ROM into RAM for faster access, but most of the new Flash BIOS chips available today are fast enough to not require any shadowing. If you are using an older video card model (e.g. not equipped with a flashable BIOS), however, you may want to enable this feature.
Typematic Rate Setting: Determines the response time of your keyboard. Generally, you want to keep this as fast as possible, therefore going for the highest rate available with the lowest delay time.
General timing tips: When dealing with timing values (such as DRAM Read Burst Timing, DRAM Write Burst Timing, SDRAM RAS# Timing, SDRAM CAS# Latency, etc.), it is best to keep values at the most stable and fastest settings. Note that I mention stability first – it makes no sense to run 5% faster and crash every now and then.
Passive Release: Leave enabled for better performance, disable only if you are experiencing problems with this setting.
Delayed Transaction: Leave enabled for better performance, disable only if you are experiencing problems with this setting.
16-bit/8-bit I/O Recovery Time: As a general rule, set all wait states to a stable and lowest value. Note that stability is the key here. If your BIOS can get you as low as 1 wait state and your system is running perfectly fine, go with the setting.
Video BIOS Cachable: Like Video ROM BIOS Shadow, you should generally leave it disabled. This also goes for all the various memory locations in this section – unless you know that a device specifically uses that particular memory segment, leave them all disabled.
Memory Hole: Leave disabled unless you have a device that particularly requires this setting.
IDE Ultra DMA Mode: If you know your hard disk's setting, set this feature to the correct value. Or just leave it on Auto.
IDE PIO/DMA Mode (Master/Slave): As above, set it to the correct value or just leave it on Auto.
Not exactly a performance-boosting feature, but you may want to disable power management entirely unless it is a concern (such as on a portable unit) to avoid situations where your system may power down during a game simply because your system did not register joystick/gamepad input signals!
Some motherboards also provide a CPU and motherboard temperature gauge which you may use to check the effects of overclocking.
PNP & PCI Configuration
The only important thing to worry about here is PCI Latency Timer. This value is subject to debate, so I suggest you try different values and benchmark your system to determine the best setting for your system. However, I don't think you'll gain any significant performance boost here, so you may as well leave it at the default value (usually 32—64 depending on manufacturer) with minimum penalty.