The Extreme4 has a very clean design and there is enough space left between the first and second PCI-Express 2.0 x16 slots for installing video cards with beefy cooling setups:

To the right part of the board, we can locate the nuvoTon IO controller:

Near it, we can also find the Realtek RTL8111E Gigabit Ethernet controller:

The sound interface is provided by the Realtek ALC892, a 8-channel HD audio CODEC:

Between the VRM heatsink and the first PCI-Express x1 slot, we can find a MOLEX header, along with two 3-pin fan headers:

On the bottom, we can find lots of other headers (from left to right):

-Front Panel Audio Header

-COM Port Header

-Floppy Connector

-Infrared Module Header

-Front Panel IEEE 1394 Header

-3xUSB 2.0 Front Panel Headers

-1xUSB 3.0 Front Panel Header

-Chassis Speaker Header

-System Panel Header

The Asmedia ASM1083 is located between the two bottom PCI-Express 2.0 x16 slots and it is a x1 PCI Express to 32-bit PCI Bridge; this controller was installed because the P67 chipset does not support PCI lanes anymore and ASRock gives a chance to people that still have good cards on this interface to continue to use them (TV tuners, audio cards and so on):

One of the EtronTech EJ168A USB 3.0 controllers can be found on the low right side of the board, near the USB 3.0 Front Panel Header; the second identical controller can be found between the VRM and the I/O panel connectors:

A LED display, named Dr. Debug by ASRock, shows us the states through which the motherboard passes during boot time, but also error codes:

On the right side of the PCB we can find the Power and Reset buttons (which are very useful when testing up the board, before inserting it inside a case), along with the 64Mb SPI Flash UEFI chip:

The SATA connectors are color coded, the blue ones being SATA2 and the white ones SATA3:

Near the ATX Power connector, we can find another 4-pin fan header and a Clear CMOS jumper: