striker10001 :
twoboxer what if i mount the rear chasis fan on cpu cooler using some adesive paste the RPM of chasis fan is 2250-70 , CPU'S fan is 2760-90 will there be any positive result....
The stock cooler does a known job within a known environment. Changing its fan isn't likely to do anything positive.
Your case's original airflow has two problems:
1) The three largest of your four fans blow IN, a small one blows out. You can't put more air into the case than you let out.
So, the amount of air going INTO your case is limited to the amount the little fan pulls out, plus what leaks out through the various seams and cracks in the case. It's likely you have a large amount of positive pressure inside the case and you are likely NOT getting as much air into the case as your three fans would suggest.
2) Even when air moves through your case, the position of the fans is stopping the hottest air from moving out quickly.
Your only exhaust fan is the small side fan. Since the fan above it blows IN and is LARGER, most of the air coming out the small fan is the air just brought in by the large fan. What air is moving past your CPU? My fear is not much, mostly whatever can squeeze out through the front of your case.
By changing the fans around, we should get positive air pressure and air flow from outside your case, past the cpu, and out the rear (and top).