The motherboard firmware is the first program that runs at power-on: it initialises the processor and memory, detects the drives and hands control to the operating system. Out of habit it is still called the BIOS, even though on modern PCs it is UEFI firmware, with a graphical interface and mouse support. Many people never open it, and that isn't always bad: the default settings are designed to work. But some options deserve attention, especially after a build or a component swap.
How to get in
You usually press a key right after power-on, before the system logo appears: Del or F2 are the most common, while some manufacturers use F10, F12 or Esc. With Windows fast startup it can be hard to catch the moment; in that case go through Settings, Recovery, Advanced startup, then Troubleshoot and UEFI Firmware Settings.
Almost all boards offer a simplified mode and an advanced one. Before changing anything, it's worth photographing the main screens with your phone: it's the quickest way to know how everything was originally.
Memory: XMP and EXPO
This is the setting most often left wrong. RAM modules start at a cautious standard speed, lower than the one advertised on the box. To make them run at the rated frequency you have to enable the profile stored in the modules themselves: it's called XMP on Intel platforms and EXPO on recent AMD ones (some AMD boards name the feature differently, for example DOCP).
After enabling it, check that the frequency shown is the expected one and that the system is stable. If freezes or reboots appear, you can go back to the standard profile or pick a less aggressive one. On some platforms the first boot after a memory change takes longer: the system is "training" the parameters, and that's normal.
Boot order and boot menu
The Boot section determines which drive to start from. After installing the system, the main drive should be at the top of the list. To boot once from a USB stick, for example for an installation or a diagnosis, the boot menu is more convenient, called up with a dedicated key at power-on (often F8, F11 or F12): it doesn't change the permanent order.
A related option is the firmware's Fast Boot, which skips some checks to speed up startup. It's convenient, but it can prevent USB keyboards from being recognised in the early stages: if you can no longer get into the firmware, that's often the reason.
Secure Boot and TPM
- Secure Boot ensures that only bootloaders signed with recognised keys run at startup. It protects against malicious software that inserts itself before the operating system. Windows 11 requires it; many popular Linux distributions support it. Leave it on unless you have specific needs.
- The TPM is a security module that stores cryptographic keys, used for example by disk encryption. In modern PCs it is built into the processor and enabled in the firmware, under names such as fTPM on AMD or PTT on Intel.
Be careful: if the drive is encrypted with keys tied to the TPM, some firmware changes, including an update, may cause the recovery key to be requested at the next boot. Make sure you have it saved before you start.
Fans and temperatures
The monitoring section shows temperatures and fan speeds. Here you can set fan curves: low speeds at idle, rising with temperature. It's the most effective way to get a quiet PC without extra software. A practical rule: leave a generous margin, and avoid fans stopping completely under load.
Other options worth knowing
- SATA mode: AHCI is the right one for almost everyone; changing it after installation can stop the system from booting.
- Virtualisation (VT-x, AMD-V, SVM): enable it if you use virtual machines or certain system security features.
- Behaviour after a power loss: useful on a home server, so it restarts by itself when the power comes back.
- Firmware password: stops others from changing settings or booting from a USB stick. Note it down somewhere safe.
Updating the firmware
Updates fix bugs, improve compatibility with memory and processors, and close vulnerabilities. But an interrupted update can leave the board unusable, so:
- download the file only from the support page for the exact model, revision included;
- read the notes: some updates require an intermediate step;
- use the tool built into the firmware, from a FAT32-formatted USB stick, rather than Windows programs;
- don't switch off or touch anything during the procedure; on a laptop, keep the charger connected;
- after the update, settings may return to defaults: recheck XMP, boot order and fans.
Some boards have a recovery feature with a dedicated button on the rear panel, which lets you update even without a processor installed. It's worth knowing whether yours offers it.
When something goes wrong
If after a change the PC no longer reaches the startup screen, you restore the defaults with a CMOS reset: a button on the back, a jumper on the board shown in the manual, or by removing the coin battery for a few minutes with the PC unplugged. In my work, before looking for hardware faults after a firmware change, I always do this step: it solves more cases than you'd think.
In short
- Enable XMP or EXPO so the RAM runs at its rated speed, then check stability.
- Use the boot menu for occasional boots, without changing the permanent order.
- Leave Secure Boot and TPM on, and save the drive's recovery key.
- Update the firmware only with the correct file and without interruptions.
- A CMOS reset is the first remedy after a wrong setting.
