4
To the left side we spot four SATA2 connectors and (gray) two SATA 6G connectors, the motherboard makes use of an extra Marvell 88SE9128 A 6G controller that provides another two SATA 6G ports. Then another JMicron SATA 2 controller is added as well for the eSATA ports.
The light blue connector just under the lower DIMM slot is for the USB 3.0 frontpanel header, that actually is the new standard USB 3.0 header specified as form factor. Sitting next above it is one of the two NEC USB 3.0 controllers.
At the center we see a diagnostic POST LED showing function codes of the motherboard, I have not checked all manual pages, but the corresponding code explanations seem to be missing in the manual. We spot a Nuvoton NCT6776F Super I/O above the POST LEDs, and the ASUS TPU chip is to the right. TPU is a small micro-processor on the motherboard that makes overclocking more easy
When we flip the board around once more we spot low level connectivity like extra USB 2.0, audio headers and so on. Audio itself is handled by Realtek's 889 codec allowing 8 channels of audio, pretty much the standard norm these days on motherboards. We would like to see some more development done on the audio side of motherboards.