BIOS Overview

“BIOS,” like “MODEM,” is technically no longer the correct terminology when referring to on-motherboard firmware. These days, the UEFI standard has assimilated all motherboard firmware into its stack.

UEFI introduced “visual BIOS” originally, first by enabling the mouse in this pre-boot environment, but has expanded to offer fan curve creation and tuning options. BIOS (Basic Input/Output System) is accessed before booting into any form of operating system or bootable media (USB key, CD). Boot splash screens will reveal the correct key to access UEFI, but it’s normally ‘del,’ sometimes F2 or F12.

What does BIOS do?

Booting into UEFI (or BIOS) provides a pre-boot list of lower-level configuration options that are managed by the firmware. All settings in this environment are stored to the CMOS battery – a round, silver battery on the motherboard – and can be cleared easily by removing and re-inserting the battery.

BIOS is responsible for configuring memory speeds, CPU and memory overclocks, tertiary timings, boot order, fan speeds, and more. BIOS is a powerful tool for getting the most out of your PC; it’s intimidating at first – moreso in the days before visual BIOS – but can be tinkered with as much or as little as desired. That’s the beauty of playing with BIOS (and building a PC, for that matter).

UEFI is a better version of BIOS, and it’s what you’ll almost certainly be using. Unlike BIOS, UEFI is capable of interfacing directly with the Host (operating system), thereby enabling software control over UEFI from within Windows or supported operating systems.

BIOS Overview

We’ll soon be using BIOS to configure boot order, but it’s also useful for other purposes, for example:

  • Power consumption controls
  • Power failure response
  • Enabling or disabling PCI-e devices
  • CPU multiplier control
  • CPU BCLK control
  • CPU vCore control
  • DRAM & CPU OCing
  • Securities & pre-boot password or biometric control
  • Noise management through fan speeds

UEFI will normally report its own version of CPU temperatures, but tends to be inaccurate when compared to software suites you’d run from Windows. Still, it’ll provide a baseline – if you’re seeing this number rise rapidly, it may be the case that the CPU fan or pump was not plugged in correctly.

Interestingly, some new versions of UEFI-enabled BIOS are providing network tools that allow remote access to UEFI. This means that support technicians could remotely configure your firmware by accessing it through a user-initiated support request. This used to be impossible, as old BIOS did not understand networking or remote access in this regard.

UEFI has grown considerably and will only continue to improve. Check back for our next guide on configuring your firmware settings correctly. This stuff matters – selecting the wrong SATA mode, for instance, can severely hinder the performance of some SSDs. The same is true for toggling certain settings or modes with PCIe. RAID is configured with different utilities, depending on the motherboard. On motherboards with multiple SATA controllers, it is important to check that the drives intended for RAID are attached to the same controller, as recommended by the manual. Ctrl+S often enters RAID configuration utilities, but it depends on board.

RAID 0 will offer striped performance without data redundancy. This increases speed at the risk of total data loss if one drive fails or falls out of RAID. RAID 1 offers mirrored performance, which can slow down speeds, but creates a duplicate of the drive as it is used (for backups). If one drive fails, the other can take over. RAID 5 offers striped and mirrored drive configurations (minimum of 3 drives), which retains the safety of RAID while still offering a slight speed increase. RAID 10 is the ideal setup, but requires more drives and is the most expensive. – Steve Burke, GamersNexus