High Idle Temps 2500k W/ N520

[alpalpa]

I am building my first computer, and have bought a CoolerMaster N520 for my 2500k system. At default 3.3 Ghz I am getting temperatures at around 47 C.
I used Artic Silver 5 (about a grain of rice in size)
Anyone know why this is happening?

 

[4ghz]

remount. When you take off the heatsink look at the spread of the paste. Is there good coverage? A grain of rice sounds a bit small. I usually use the size of a small pea.

 

[alpalpa]

I remounted it and added a little more thermal compound. It idles at around 43 which is still a little high.

 

[86waterpumper]

load temps are alot more important so I would check those. Maybe the fan is turning a slow rpm?