To all the air coolers: do you have fans on the top of your case?
I currently have plans to buy 3 fans to add to the 2 that already come with the case, yet do I really need to have 2 of them on top of the case if I'm air cooling my CPU ?
Any input would be greatly appreciated!
I think to answer properly we need more information, Which case do you have, and what is your current fan setup? to answer incorrectly in short no.
Airflow is normally from front to back adding air intakes and exhausts that disrupt this intended flow take away from the cooling potential of the system. Normally fans on the top of a case are exhausts they bring the air from the front up around the CPU socket area and out the case. These are normal intended for radiators to exhaust heat rather then for air coolers. The space at the rear most top fan slot may help your intended airflow by pulling hot air out that cannot be exhausted out the back limiting any dead air zones.
Without information on the case you have I really couldn't say but follow the general guidelines and you will be fine. Also if you are concerned about Airflow you might be better off upgrading the intake fans in the front of the case and the exhaust fan on the back that will ensure you gain some performance.
Lastly keep in mind upgrading fans and adding them when you already have the airflow you require does nothing and will be just about the worst price to performance thing you can possibly do.
Also always use the right fans in the right places there are two kinds Air flow and static pressure afterwords known as AF and SP respectively AF fans push air straight back from the blades creating a concentrated cone of air which has a long range these fans perform best when there is little to no obstructions and serve as air accelerators forcing air towards your components. AF fans lose effectiveness dramatically when obstructions are present. SP fans force air back from the blades creating a large cone of air but do so with great air pressure they are used for when there is obstructions, I.E. heatsinks hard drive cages, radiators. These fans project the air in such a wide cone that their effective range of usage is very low because the air they exhaust is so unfocused it spreads like a wide V or cone. They are best as exhausts, on heatsinks/radiators, and as intakes with AF fans behind them on highly obstructed cases. There does exist fans that do both of these tasks and are somewhat interchangeable however, they are more costly and aren't as focused so don't really excel at any one task.
Dude, thank you so much for this information. This really helps me out.
The case is a 350D by the way. I had planned to add a 140mm AF fan to the front of the case along with the 140mm fan that already comes included in the front. The case already comes with an 120mm fan in the rear position. As the case is corsair, and it's fans are as well, I assume that they'd do an exceptional job at the task I intend for them.
Again, thanks so much for the info man
No problem great choice of case! To add one 140/120 to the front will help your graphic card/s breath and will really be ideal you shouldn't need anything more then that on a case that size! The corsair stock fans are alright the 140mm are actually quite good.
Best of luck with your build!
Those were my thoughts exactly. Thank you very much for your help man; greatly appreciated