IBM BDM-610000049 Features and Settings That Can Affect Boot Time, Quick Boot, VGA Controller

Features and Settings That Can Affect Boot Time

The boot time of a system is dependent upon numerous system settings as well as devices attached to a system. This section addresses some devices and settings that can increase or decrease a system’s boot time.

Quick Boot

The BIOS contains a Quick Boot option that minimizes the boot time of the system. Quick Boot eliminates the exhaustive tests that are performed during Power On Self Test (POST) while maintaining the functionality of the board. By enabling the Quick Boot feature, your system can achieve 5-second boot times.

Add-On Cards With BIOS Extensions

Some add-on cards have an integrated BIOS extension. The most common examples are SCSI controllers and network cards with boot ROMs. During POST, the BIOS executes the card's extension code. This extension code is third-party code, which is beyond RTD's control. The BIOS extension will most likely increase the boot time. Exactly how much it increases boot time will depend on the particular card and firmware version.

VGA Controller

VGA controllers have a VGA BIOS that must be initialized during POST. It can take some time to initialize the VGA BIOS. Exactly how long will depend on the particular VGA controller and BIOS version.

Hard Drive Type

During IDE initialization, each IDE device must be probed. Some devices take longer to probe. 2.5-inch hard drives tend to take longer than 3.5-inch ones, because they spin at a lower RPM.

Monitor Type

Some monitors take a while to power on. Desktop flat panels are especially slow. This does not affect the actual boot time of the CPU. However, the CPU may boot before the monitor powers on.

NVRAM Updates

System configuration data is stored in the onboard NVRAM. When the system configuration changes, this information must be updated. If an update is necessary, it will happen at the end of POST (the BIOS will display an “Updating NVRAM…” message). The NVRAM update takes a few seconds and increases the boot time. Once the NVRAM is updated, boot times will return to normal.

NVRAM updates only happen when the system configuration changes. They do not happen spuriously. They are usually triggered by adding or removing a PCI device from a stack. Updates can also be triggered by altering the Plug-n-Play configuration of the BIOS.

Boot Device Order

The BIOS contains a list of devices to try booting from. If you wish to boot to a particular device (for example, a hard drive), make sure that it is first in the boot order. This will speed up boot times.

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