Fan setup in Obsidian 550D

[Heimdal]

So I'm planning on building an Ivy Bridge and GTX680 setup in this case in the near future. The plan is to upgrade to SLI sometime later if necessary, but for now I will have just the single card. I was hoping to do some overclocking, and to that end I'm going to buy a Noctua NH-D14 for the CPU and I also intended to buy a couple of extra fans for the case. I'm hoping to get some OCing done without my system sounding like a jet engine.

I was thinking I would leave the 3 fans that come with the case in, and buy two Thermalright TY-140s (tested well here: http://www.xbitlabs.com/articles/coolers/display/140mm-fan-roundup.html) to put somewhere.

After some research it seems that putting them on the side as intake fans would be the most beneficial (though I'm not sure I could fit both, or even one, with such a big tower cooler on the CPU). I was also considering whether a 200mm fan would be better, but I've heard that the 200 mm fans are not very well developed, so 140s perform better for the same amount of noise. I've heard 120s are even better developed than 140s, but I assume that just the size would still let the 140s win?

Would be great to get some input on this. Thanks!

 

[grambo]

Hah, I am planning a very similar build to you: 3770k OC'd with an NH-D14, single GTX680 (non-reference, waiting for the dual fan EVGA or MSI Twin Frozr model to come out) in a 550D.

My plan is to run the stock fans (2 front intake, 1 rear exhaust), plus a bottom intake in front of the PSU, although I haven't decided what model fan to use there yet. I plan to leave the side and top vents covered to reduce noise. I'm hoping this config will move enough air to allow overclocking on the CPU and GPU when they are under load and I will be using the power management features to scale them down at idle as both the CPU and GPU support this. This setup will be "positive pressure" and hopefully reduce the amount of dust getting into the case (we have a cat so lots of dust/hair - I vacuum the floors/filters weekly). If this isn't enough airflow, I would probably add a fan to the side panel first since it's farther away from where I sit compared to the top.

I plan on running all 6 fans (4 case + 2 CPU) on motherboard fan headers using Asus FanXpert 2 fan profiles to ramp fan speed with temperature. My goal is for max performance when gaming with reasonable noise (I don't need silence when gaming, but I don't want jet engine noise either) and near silence at idle.

 

[Heimdal]

Sounds great grambo, pretty much the same goals as you. I also wanted to use the PWM control of the motherboard. I've been drooling on the Palit GTX680, you seen that? Looked pretty cool in tests.

The reason why I was thinking side fan is because of this article: http://www.bit-tech.net/hardware/2012/02/10/the-big-cooling-investigation/1 that seems to indicate that side fans are very effective for lowering temperatures. But not sure it would fit with the cooler..

Did you check out the 140 mm fan roundup I posted? I found that pretty helpful.

 

[Heimdal]

Got some input on the side fan situation. Apparently there is space on the bottom mount for a fan, but not the top one. So maybe I can put one fan on the bottom side (my GPU will presumably be happy) and one on the bottom mount. Because as you say, it's not so important that it's silent when gaming etc, and as long as I can control the speed of the fans I should be ok.

Btw grambo, you know that the stock fans are non-PWM right? Can you still control them with the motherboard then?

 

[grambo]

Got some input on the side fan situation. Apparently there is space on the bottom mount for a fan, but not the top one. So maybe I can put one fan on the bottom side (my GPU will presumably be happy) and one on the bottom mount. Because as you say, it's not so important that it's silent when gaming etc, and as long as I can control the speed of the fans I should be ok.

Btw grambo, you know that the stock fans are non-PWM right? Can you still control them with the motherboard then?

Thanks for posting that 140mm round-up, will take a read a bit later, it looks very comprehensive in terms of testing methodology!

Good to know that one side panel fan can be used, that would be my next choice if I figure out that I need more cooling than the stock setup + 1 bottom intake. Better than opening the top IMO.

I was actually researching this morning and I think you are right, the 550D stock fans are 3-pin only, so I'm not sure if a mobo header can control them or not. Definitely not with PWM, but I think they can still be voltage controlled? I don't understand if PWM and voltage control are the same thing or not, need to do more reading. Looking into it, as I don't really want to spend $30-40 replacing the stock 3 fans on a brand new case if I don't have to.

 

[Heimdal]

Yeah that's why I like it, because if you don't have the same setup for every fan they're impossible to compare in any meaningful way.

I also think the side fan gives a bigger benefit in terms of temperatures than the top fan, since then you would be putting air directly where it's needed.

PWM controls the fan speed with something called pulse width modulation. I think this means the fan has a built in controller that sets the speed depending on the pulse widths on the 4th pin, which is a signal it gets from the motherboard. Voltage control just means that you have to change the fan voltage depending on the RPM you want. I think there are many motherboards that have this option built in, but it is probably worth checking before you buy the motherboard if you haven't already..

 

[bloodyredd]

Finally! I also plan to do this build in the future. What do you guys think of putting up a fan at the top and side panel? I've read that having more than 3 or 4 fans is somewhat beneficial but it has diminishing returns.

Here's the link for the article: http://www.bit-tech.net/hardware/2012/02/10/the-big-cooling-investigation/1