What is normal RPM fan speed for 35c-45c CPU temperature

[instantfameorgame]

My fan speed was constant 2300 RPM on idle so I went into bios and turned the fan down, it now sticks to 1100 RPM and 35c idle and 40c-50c with the same speed. I was wondering if 1100 RPM was fine for 45c or if I should turn my fan back up

 

[jay.wooster]

What CPU and is it a stock CPU Cooling Fan or specialist ? Quite hot for idle temps....