Acer H81h3-am V1.0 Manual -

While visual confirmation is always recommended, the standard Acer pinout for this generation usually follows this layout (viewed with the board oriented with the I/O ports to your left):

Before diving into the BIOS, here are the raw specs you would find in Section 1 of the missing manual. Acer H81h3-am V1.0 Manual

The Acer H81H3-AM V1.0 uses an . It is visually basic, but hidden settings exist. To enter BIOS, press F2 repeatedly during boot (or Del on some variants). To enter BIOS, press F2 repeatedly during boot

Intel Core i7-4790 (Haswell Refresh, 4C/8T, 4.0 GHz Turbo) Note: The VRM (Voltage Regulator Module) on the H81H3-AM has no heatsinks. Do not install a 84W TDP i7-4790 without active airflow over the motherboard. An i7-4790 S (65W) is safer. An i7-4790 S (65W) is safer

Avoid fake "driver updater" software that claims to have the manual. They are malware.