How many fans do I need/is a fan controller necessary?

[MJK4Y]

Build:
Cooler Master HAF 912
(2x4GB) G.Skill Ripjaws series RAM
i5 2500k
Hitachi Deskstar 750GB

Waiting for Kepler before deciding on a video card and motherboard, but maybe either that or a GTX 570/560.
Leaning towards an ASRock z68 extreme 3 gen3.

Right now, I have a 120mm rear exhaust fan, and a 120mm side intake fan. I am considering putting in a third, 120mm top exhaust fan, but I wanted your opinions. Does the third fan seem necessary? I plan to overclock the RAM a little bit, and maybe the CPU a little later on when I can afford a new heatsink for it too. I will be gaming on this computer.

If I do get a third fan, does it make sense to buy a fan controller and hook them all up to that?

Not sure how to proceed.

Edit: I read some accounts of fan controllers failing and a person's computer getting fried as a result. While I'm sure that's a relatively rare occurrence, it's enough to turn me off from using a controller, unless you guys think it is a good idea.

 

[T_Yamamoto]

you dont need extra fans
you dont need a controller

 

[Charlie98]

I would go ahead with your plans to OC, and then monitor your temperatures. If your CPU cooler is a good one mounted correctly and you start getting high temps, then you can look to a solution for that.

My HAF922 has 2x 200mm fans and 2x 120mm fans, plus 2 fans on the CM 212+... but I found the extra case fan and even the extra CPU fan had very little effect on temps. The caveat to that is I don't have the heat of a GPU, yet, so that may help in the long run once I get a GPU.

I use a Lamptron fan controller... not to regulate cooling, but to regulate the FAN NOISE and dust... I see no reason to run all those fans at normal compute loads. At this point, I have just the bottom case fan on about 50% and the 200mm top fan on about 50%, the rear case fan and the CPU fans are run by the mobo (although next time I open it up, I'm switching the CPU fans to the controller.) I like the flexability of the controller and believe it is a pretty solid unit.... but I did my research and spent the money on a good one.

 

[Elcs]

Never easy to tell.

I like having front intakes keeping my hard drives cool and that air goes directly into the GPU area so that's probably the area I'd consider placing an additional fan (low speed).

Personally, I'd probably buy all the kit, test it out and see what your temps are like. Make decisions based on results, not on something entirely theoretical.

 

[lehtv]

If you're running the fans at a normal 1000 RPM or so then I don't think there's a huge need for new fans, though your temperatures could be lower with another intake and exhaust. I would place intakes on the front, nothing on the side.

If on the other hand you want to make your setup quieter but still retain overclockability and decent airflow, you're going to have to buy more fans and then downvolt them, and the most practical solution to that is a fan controller. I have my case set up with five downvolted fans - the fifth one probably isn't necessary but I had up to eight fans at one point for experimenting purposes. I tried to find a sweet spot for case fan noise and GPU fan load noise. Less case fans was better on idle, but 4-5 was needed to get the GPU fan quieted down at load.

In any case, I agree with Charlie98, just go ahead with the OC and see what happens. If the temperatures aren't what you expect and want, then buy a couple more fans.

I plan to overclock the RAM a little bit

FYI you don't need to OC the RAM, just run it at its rated speed. RAM overclocking would benefit you so little that it'd be pointless.

If I do get a third fan, does it make sense to buy a fan controller and hook them all up to that?

Not unless you want to quiet the fans down. If you're fine with the noise your current fans make, just buy another one with the same approximate rpm and noise ratings. If you don't have slots in your motherboard for additional case fans, you can buy a fan that connects directly to your PSU, or you can use a splitter cable.

Edit: I read some accounts of fan controllers failing and a person's computer getting fried as a result. While I'm sure that's a relatively rare occurrence, it's enough to turn me off from using a controller, unless you guys think it is a good idea.

That's a pretty irrational fear. There are risk factors in everything, and nothing suggests that a controller failing is in any way common enough to affect your decision buying one.