Why do so many cases have 80 mm fans?

[thelastmccabe]

I'm new to all this and am working on building my own pc and have been spending a ton of time online figuring stuff out, but the case is giving me a lot of trouble. What makes no sense to me is that so many cases come with 80 mm fans. I keep seeing cases that look just right...and then they have 80 mm fans! My impression from this site and others is that 120 mm fans are quieter at the same level of cooling and are capable of providing more cooling overall...basically there is no reason to get 80 mm fans because 120 mm ones do everything they do better (in general, im sure that there are really expensive 80 mm fans that do whatever you want). But 80 mm fans must do SOMETHING useful, or otherwise no one would make cases with slots for them, right? I mean, no one would use them at all if they weren't any good...but people do...so why? If anyone could enlighten me on this I'd really appreciate it...thanks.

 

[CalvinHobbes]

80MM takes less space. That may be a factor when designing the case. Cost may be a factor as well. My TT Tsunami has 2x 120MM and 1x 92MM.

 

[steamnputer]

80mm(or 92mm in tt's) vs 120mm besides what calvinHobbes stated also have different volume/speed curves, if you have the same poled 80mm fan it will move air faster(speed or velocity not volume or amount) then a 120mm typically(but not always there always exceptions). If you are seeking volume, 120mm is the way to go, most cases only have space for 80mm though and 120 mm seems to be a relatively new trend.
steamnputer

 

[imported_rod]

80mm fans are smaller and cheaper. they fit in smaller cases, where 120mm's wouldn't fit. They also make less noise for the same RPM's.

Anyway, most people dont need anymore case cooling than one or two 80mm fans. My DADs p4 has a single 80mm exhaust fan, and thats all it needs, even in the hot Australian summer (we have days over 40C here in the summer. The hottest day at my place last summer was 46C/115F).

RoD

 

[JE78]

I have 4 80mm and 1 120mm. The 120mm is quite loud but I just got a temp monitor/fan controller and all I have to do is turn it down a few hundred RPM's and its pretty quiet. The only reason I went with the 120mm was because it was free. A good 120mm can run you $15, $20. Here's a question I was wondering. I have 3 left over 80mm fans. Would it be ok to drill a few holes in the side of the case and mount a fan or two? The reason I ask is because i've always been told to have a intake and exhust of 1:1. Right now I'm at 2:3. Thanks.

 

[Promethply]

Originally posted by: JE78
I have 4 80mm and 1 120mm. The 120mm is quite loud but I just got a temp monitor/fan controller and all I have to do is turn it down a few hundred RPM's and its pretty quiet. The only reason I went with the 120mm was because it was free. A good 120mm can run you $15, $20. Here's a question I was wondering. I have 3 left over 80mm fans. Would it be ok to drill a few holes in the side of the case and mount a fan or two? The reason I ask is because i've always been told to have a intake and exhust of 1:1. Right now I'm at 2:3. Thanks.

Unless your system's overheating, adding additional fans will not significantly lower your case temperature.

 

[JE78]

At idel my case temp is 27c, 28c at load its 32c max. Here's another question. I left my computer on all last night, when I got up this morning the temp on the CPU was 41c, i've only seen it that high when the CPU is under load. The only thing I had running was Azureus bit torrent client. As soon as I got out here and turned my monitor on the temp droped to 30c. Any reason why it would be so high when I'm not even using it?

 

[Promethply]

What's your system setup like -- location of your case, type of CPU, case brand/name, etc, etc?

 

[imported_Kensai]

The 80mm seem to be the "standard" size for most cases.

 

[JE78]

Originally posted by: Promethply
What's your system setup like -- location of your case, type of CPU, case brand/name, etc, etc?

My case is in the corner of the living room, nonthing is blocking the air flow. Here are my specs:

P4 2.53
Gigabyte GA-8SG667
ATI 9800 Pro APG
512 PC2700 Generic, 512 PC3200 Crucial. 1GB total running at 2700
2 200gb Westren Digital HDD
Sound Blaster Live 5.1
Enermax 460 watt PSU

 

[Promethply]

Originally posted by: JE78

Originally posted by: Promethply
What's your system setup like -- location of your case, type of CPU, case brand/name, etc, etc?

My case is in the corner of the living room, nonthing is blocking the air flow. Here are my specs:

P4 2.53
Gigabyte GA-8SG667
ATI 9800 Pro APG
512 PC2700 Generic, 512 PC3200 Crucial. 1GB total running at 2700
2 200gb Westren Digital HDD
Sound Blaster Live 5.1
Enermax 460 watt PSU

The Azureus bit torrent client is probably quite CPU intensive? -- but otherwise, your temps are OK.

 

[JE78]

Thanks. So what temps are safe for the CPU and GPU under load? So far the highest i've seen for the CPU was 42c under load and the GPU was 48c under load.

 

[frx218]

80mm fans are faster, take less space, cheaper, and fit a lot better.

 

[charlietee]

As case design has evolved manufacturers have been moving towards 120m/m fans...120m/m fans will always deliver more CFM at a given Dba.

So generally speaking cases with 120m/m fans will be of newer design and usaully provide other improvments, like rubber mounted fans...rubber gromets to mount hard drives.

Seems the industry is moving towards trying to create new cases that provide better thermal performance at lower noise levels.

There are many cases that use 80m/m fans that have excellent thermal performance.

I have a PlusView Antec that I have modded to accept 92m/m fans up front in place of the standard 80m/m...Installed a 92m/m blow hole fan and drilled a hole for a 120m/m fan blowing on the backside of the motherboard right over the CPU socket, northbridge and 3 UV Reactive Antec fans, 2 in the standard rear mounts and one in the windowed door...All the fans except the 120m/m LED fan blowing on the motherboard are 7 volted.

Needless to say the thermal performance is awesome and considering the number of fans reasonalby quiet.

Since you are doing your homework on cases you will find that some of the better designs incorporate 120m/m fans...Not saying there are not good cases that use 80m/m fans.

Here are some examples of what I consider bad a$$ cases with excellent thermal performance.

Antec SLK3700B This Antec has to be one of if not the best bang for the buck cases on the planet...Cant beat it with a bat (In my humble opinion of course)

Lian-Li PC-7B Plus This Lian-Li is my favorite case at the moment...Dual 120's provisions for a 80m/m blow hole fan (fan not included)...Aluminum construction...Windowed...Nice case...Really nice.

Since you are looking at case I recommend you stick with something that incorporates 120m/m fans.

 

[imported_rod]

Originally posted by: JE78
Thanks. So what temps are safe for the CPU and GPU under load?

Which CPU/GPU are you asking about?

RoD

 

[Dough1397]

80mm are good for spot cooling... 120 mm fans have a alrge dead spot behind the hub thingy

 

[Promethply]

Originally posted by: JE78
Thanks. So what temps are safe for the CPU and GPU under load? So far the highest i've seen for the CPU was 42c under load and the GPU was 48c under load.

Your system's temps are fine

My GPU (nVidia 6600GT) idles @ 51C

And my CPU (Athlon64) idles @ 34C, and 43C under load

 

[Promethply]

Not too long ago, usually only "case-modders" installs 12cm fans in their case.

On the other hand, at the same RPM, a single 12cm fan will be louder than two 8cm fans,

while both configurations probably moves similar volumes of air.