Strange RPM fluctuations, case fan

Well I dont know if you need my full specs but here they are just in case,

Corsair Carbide Series 300R Case (a lot of room for a mid tower case, greeat airflow, and it is only $79.99)

Thermaltake Smart M750W (reused from my old build, but is fairly new, purchased back in December)

Asus Sabertooth 990FX R2.0

AMD FX 8350 4.0GHz

Corsair Vengeance 8GB DDR3 1866MHz (although it is only showing 1333 in the Bios)

500GB Western Digital Caviar Black HDD (used from old build)

Creative SB X-Fi Xtreme Gamer Sound Card (used from old build)

MSI R7870 Twin Frozr III OC Edition, GHz Edition, 2GB GDDR5

The fan that is mounted in the back top section of the case is showing strange fluctuations in RPM. I tried plugging it into fan chasis 2, 3, and 4. Showed the same behavior or maybe it's normal I don't really know. Here is a short 14 second second video of the RPM fluctuation. Look at "Fan 3"

http://www.youtube.com/watch?v=lcdFqDVGDQI&feature=youtu.be

Anyone?

No one has any idea at all?

 

the fan thimg seems normal as for your memory you need set manualy in the bios to 1866 use the profile on the memory which usaly listed at the end of the available profiles.