The most important thing is to fix your problem so what have you tried so far to improve cooling of your CPU?
1) downclock reduces heat
2) reduces performance
1 stick will reduce heat but hardly noticable.
i've clean the cpu head sink and fans with a strong blower.
my mobo temp is also high (normal 45C and max 70+.
and my 4550 fanless is 50C-70+.
so i think i need ventilation inside my case. so plz let me know ur opinion
i've one blowing 80 mm fan inward and power supply fan outward
Yeah, maybe a fresh coat of thermal paste will fix the problem.
You'll need to remove the heatsink from the CPU, then clean original thermal paste from the heatsink and CPU with rubbing alcohol and a lint free towel. The apply thermal paste (about the size of a rice grain) to the CPU and spread it evenly with something like a credit card or playing card.