Asus Crosshair IV Formula - Manual (Page 71)

2.8.6 ProbeIt
The ROG ProbeIt feature provides a nice touch for your convenient and accurate
OC settings. No time wasted fumbling around on the complicated motherboard
layout, the clearly marked area gives you easier access to the measure points
when a multitester is employed for more accurate measurements during your busy
overclocking work.
Refer to the following illustration for ProbeIt location.
Using ProbeIt
You may connect the multitester to the motherboard as shown
The photos above are for reference only, the actual motherboard layout and
measure points location may differ by models.
ROG Crosshair IV Formula 2-45