4x80mm fans v. 2x120mm fans

[LkyOldSun]

which is better
1. for noise per cfm
2. for possible cfm

looking at antec cases (chieftec rebadges) that have
2x80mm exaust back, 2x80mm intake front
or
1x120mm exaust (back) , 1x120mm intake front


PS. still considering sonata, which has only one exaust . , but want to know performance of above mentioned setups. Than

[SteveI]

A good quiet 80mm fan should blow about 35cfm @ 3000rpm. I've never used a 120mm myself, but I think people who use them, swear by them.

[cloasters]

Contrary to what tactful girlfriends say, bigger is better. Larger fans move more air at slower rpm. This is always more quiet than a smaller fan working very hard to move the same volume of air. An ~80 cfm 80 mm fan is very loud. An ~80 cfm 120 mm fan is very quiet. Athlon machines need a lot of throughput, I use at least one 120 mm intake fan in mine.

Balanced throughput is a good idea. If you have 108 cfm being drawn into the case, you want 108 cfm being exhausted from the case. A little over-pressure helps keep dust out of your box, so 108 cfm in--and 98 cfm going out may be ideal.

[Staz]

A 120x38mm Fan will be the best option for noise performance. a high flow rate fan with a fan control will give you the best option with the ability to "dial in" your noise/airflow.

[cloasters]

The 108 cfm 120 mm Sunons I have are audible. The sound they make is much closer to white noise than fan noise. My guess is that an ~80 cfm 120 mm is very quiet.

[LkyOldSun]

That's it!!!
thanks to the info here, and after much research, I am now positive that I am going to get the slk3700 in all it's bronze glory. Heck, today, I passed up $15 refurb cheapo cases and $30 chieftec refurbs (4x80mm, no psu) and $40 refurb chieftec (5x80mm, 400 PSU) among others (all the chieftec cases were server size anyway). I passed the temptation test and am sure I will be getting the Antec slk3700, with it's 2x120mm fan options. Took me bout 10 hours of research to come to this conclusion, but I thank you all for helping contribute to the knowledge I needed to make this decision.

[cloasters]

Glad to hear that you held out for the case with the right fannage. Cases pre-punched for dual 120 mm's were hard to find a while back, I hope they're easier to buy nowadays.
You might think about removing the blockage by the patterns of holes that usually obstruct fan mounts in brand new cases while the new case is empty.

This requires sweat and bother. But the cutesy patterns of holes really cut down the efficiency of the fans. A simple fan guard lets the air flow through the fans much better. A filter on intake fans is an excellent idea. If you don't live in a dustless area, cleaning the cobwebs out of a PC once a month is APITA.

[Staz]

Originally Posted by cloasters

You might think about removing the blockage by the patterns of holes that usually obstruct fan mounts in brand new cases while the new case is empty.

This requires sweat and bother.

I have found that a dremel makes quick work of this. Just cut a slit conecting all the holes in the outer most ring of holes. It leaves a scalloped look that isn't very attractive, but it is very quick and quite functional.

[LkyOldSun]

From what I've read, I need to get a dremmel and a hot glue gun for my modding adventures. (not much int soldering). I was considering buying a $20 Kragen Auto cheapie "dremel".

[cloasters]

Originally Posted by Staz

I have found that a dremel makes quick work of this. Just cut a slit conecting all the holes in the outer most ring of holes. It leaves a scalloped look that isn't very attractive, but it is very quick and quite functional.

But a needle file and a "one-handed" hacksaw make the job much more time consuming. However you remove the blockage from the fan mounts, make sure to clean up all of the bits of steel. The little chunks are obvious--it's the steel dust that will wreck your day if it's left in the case. Leaving a hole with dangerous edges t'ain't smart. But you may wish to live dangerously.

*Caution.* Wear safety goggles when using a Dremel. The cutting wheels can shatter. Pay attention to the arc of the cutting wheel. Saw a post from a guy that didn't--replacing the sliding glass door to the deck of his apartment cost him five hundred smackers.

[LkyOldSun]

Thanks for the advice. I could definitely see myself charging into this mod thing and not even think about safety, until something happpens. Now I'm gonna think twice before I start.

[cloasters]

A piece of a broken cutting wheel flew eight feet through the air and put a big, noticeable crack in the guy's sliding glass door. His landlord wasn't understanding about the cracked door.

Much more importantly, eyes can't be replaced for $500.

[LkyOldSun]

looks like his expensive mod almost became priceless. I am glad his vision was spared. The thought of eyeballs being decimated by flying bits of broken cutting wheel invokes a vision in my mind that will haunt me everytime I pick up a dremmel. Thank you, cloasters for an ancedote that makes transparent one of the dangers of using a dremel.

[cloasters]

If you don't want to buy an expensive pre-modded case, hackin' and a hewin' to make sure that a K7 processor gets plenty of fresh air is part and parcel of building a cool running machine. Doing it safely is common sense.
I haven't cut an aluminum case. Aluminum really binds on drill bits. If I ever have an aluminum case, I am inclined to let a machine shop cut it as needed!

[LkyOldSun]

my last job involved duties abound in grinding, welding, brazing, bending, cutting (with a blowtorch), drilling, tapping, and fabricating metal parts as needed. Of course, I did this for various industrial machines that I repaired, so intricate detail was usually not involved (hence why I have no dermel). Didn't work with aluminum too much (not very weldable) but I would suspect it needs to be taken slow and gentle to prevent binding or warping when working with thin sheets, like what's used to make cases. But a machine shop should be able to do a great job (and probably worthwhile for most folks to keep them from damaging an expensive case)

I don't plan on super-modding, myself, as I just want to get those punched fan covers off to allow air flow to and from my case. I figure my angle grinder is overkill, and don't have a compressor anymore for my pneumatic rotary grinder.
I noticed in the Kragen ad, a mini rotary tool kit for 12.99, and if it's good enough, cool, if not, I loose $14 after tax. http://www.partsamerica.com/PartDeta...goryCode=3483K

[cloasters]

Shucks, PartsAmerica.com isn't listed at www.resellerratings.com . Not surprising, RR lists the reputations of etailers that specialize in PC gear. Mighty good site to visit before sending the hard earned green into cyberspace.

The Dremel "copycat" kit looks like the steal of the century. I have to wonder if "steal" may be the operative word in this deal?
Part of my job in the shipyards was to hold hangers, collars and assorted other aluminum parts in place while the MIG welder made them parts of the ship. The areas to be welded together had to be very clean and shiny. Overhead welding was the best. Molten aluminum burning into the scalp was glorious. And no flinching, you had to hold that part rock steady!

[SeanK]

Originally Posted by LkyOldSun

I noticed in the Kragen ad, a mini rotary tool kit for 12.99, and if it's good enough, cool, if not, I loose $14 after tax. http://www.partsamerica.com/PartDeta...goryCode=3483K

Anyone taken the plunge on that mini rotary? It does look like a sweet deal if the performance is there. Also, the mini's big brother looks good as well, weighing in at 20$ http://www.partsamerica.com/PartDeta...goryCode=3483K

Anyone have any hands on experience with either of these?
Thanks.