two 120mm vs one 200mm case fan

[z1ggy]

Deciding which will be better for my build. See my sig for the info. Looking to keep it quiet, as I don't think I would need massive airflow b/c I am only running 1 gpu and an i3. Got my eye on a CM Megaflow for the 200mm or the CM sickleflow for a 120mm.

PS- Are the holes in the fan where the screws go threaded on these? My old Antec fans that I have I noticed aren't threaded, so I couldn't put them in my new case. Looks like I will need to thread those on my own if I want to use them.

 

[alaricljs]

Threaded? I've never had a fan with threaded holes. There are specific screws for fans that are self tapping.

edit: here's a link Jab-Tech

 

[Slugbait]

So if I understand this correctly, you already have two CM 120mm fans, which are rated at 17dBA and widely reviewed as "near silent", and you're thinking of replacing them with CM fans that are rated at 19dBA...and you're looking to keep your machine quiet?

If that's what you meant, then don't do a thing, yer fine.

 

[z1ggy]

^^ 2dB not going to make a huge difference to me seeing at the stock CM fans don't move as much as these. Additional, I would be keeping the stock, and adding 2-4 more.

 

[Evadman]

^^ 2dB not going to make a huge difference to me seeing at the stock CM fans don't move as much as these. Additional, I would be keeping the stock, and adding 2-4 more.

A 3db increase is twice as loud.

 

[Slugbait]

A 3db increase is twice as loud.

And if you're going to have six fans, forget about looking to keep it quiet...your box is going to be LOUD.

 

[Slugbait]

Also, you originally said,

I don't think I would need massive airflow b/c I am only running 1 gpu and an i3

but you should be aware that four or more fans IS massive airflow.

 

[z1ggy]

^Yeah I mean I kind of assumed I might need more b/c of the stock ones being weak. However, I ran some temp tests and my cpu is running at decent temps idle. I think I am more concerned about the gpu. Is it worth it to have top exhaust fans, or a fan on the side blowing directly on the GPU.

 

[Slugbait]

You don't want to pull in more air than you are exhausting. On the other hand, the open top of your case allows hot air to naturally rise out of the case, so a side panel fan would be my choice...

...if I were having a heat problem.

I've got a GTX460 in a Silverstone LC17, and have no problem with heat while playing CoD : WaW at 1080P. My case doesn't have an intake fan, just a couple of 60mm exhausting near the CPU.

Your case has an air supply next to your card. The card's fan will naturally draw in air from that source. I'd recommend you put a load on it and check the temps before simply adding fans. I doubt you're going to see a heat problem.

 

[BonzaiDuck]

It seems that we settled this issue about noise a few years back. As I recall, the dBA of more than one of a particular fan is not additive. I also I doubt you would notice much difference between 17 and 19dBA. CFM, however, should be roughly additive.

Second, there is another factor that works against the larger fans: the static pressure spec. If you pressurize your case with fans of a low static pressure, I suspect you would find regions of the fan's intake area where air is actually escaping opposite the direction of the fan's airflow.

But if you can move 70 to 90CFM with each 200mm fan, I'd gather any one might be better than two 120mm fans moving less than 35CFM each.

 

[Patrick Wolf]

^Yeah I mean I kind of assumed I might need more b/c of the stock ones being weak. However, I ran some temp tests and my cpu is running at decent temps idle. I think I am more concerned about the gpu. Is it worth it to have top exhaust fans, or a fan on the side blowing directly on the GPU.

Side fan is better. But ideally you'd want something on the top too. I'd probably just go with the megaflow, leaving the side clear cause I highly doubt you'll have any heat issues. You don't need a super cool GPU. Take my rig for example, for awhile I was only using one low RPM front intake. No exhaust fans. My GPU's fan speed is capped at 43% and it was Kombustor stable.