[Official] Cooler Master ATCS 840 Owners Club - Page 27 - Overclock.net

Meijer · 07-01-09

I suggest you read this test. The Noctua's NF-P12, nor the NF-S12(A/B) don't perform as good as they are supposed to do. This has been reported so far in several extended reviews. The open-air performance of these fans comes close to the specs perhaps, but when you put a mesh/filter/anything else in front of it, the fan simply collapses. Besides, a lot of users also report a buzzing sound, where other fans would have become inaudible. The Noctua NF-P12 is one of the better Noctua fans though, and it is indeed more efficient in terms of air movement per rotation than other fans, especially on lower speeds. Above 600/700 RPM, the efficiency is reduced though. If you get these, I would undervolt them to either 7V or 5V, preferable the last option.

Having said this, Scythe Gentle Typhoons are an excellent choice: very high-quality ball-bearings and very well balanced, which makes it one of the, if not the most, efficient fan when it comes to produced noise per rotation per minute. The Scythe S-Flex has a better efficiency when it comes to moved air per rotation per minute, though also more noise. Both are excellent fans and cheaper than the Noctua's. The Noctua's only come with a ton on accessoires however, like fan adapters, shock absorbers and a warranty of 6 years which might also not be too bad...

Another option is that you just keep the standard fans: it's been reported the standard 230mm fans are quite good in terms of noise and air movement, especially when undervolted to 7 V for example.

Just keep in mind that in the end a piece of plastic is supposed to make rotations to move a piece of air. There aren't very large differences between generally good fans. They are all good options. You should only avoid bad designs which make the fan more noisy than others, especially bearing noise and engine noise is extremely irritating. Most good fans don't have this however.

Mezzler · 07-01-09

I would agree with meijer on keeping the 230mm intake. That is a monster 110cfm with little/no noise. You wouldnt get any better airflow there with 120mm fans. And i doubt it would be any quieter. Also, when i first built this rig, i had the noctuas in it. I was trying for a quiet build. It was quiet, but not as cool as it could have been. So much dead space in this ATCS case...was really more than the noctuas could handle. You definately need better fans than 54cfm ratings if you want to cool this monster down.

Mattb2e · 07-01-09

Quote:

Originally Posted by Mezzler

I would agree with meijer on keeping the 230mm intake. That is a monster 110cfm with little/no noise. You wouldnt get any better airflow there with 120mm fans. And i doubt it would be any quieter. Also, when i first built this rig, i had the noctuas in it. I was trying for a quiet build. It was quiet, but not as cool as it could have been. So much dead space in this ATCS case...was really more than the noctuas could handle. You definately need better fans than 54cfm ratings if you want to cool this monster down.

Actually the 230mm fans are 150cfm, so they move much more air than a 120mm does, The only way you could get better air volume with a 120mm is by living with lots of noise. The 230mm are very quiet, I would just stick with them.

Meijer · 07-01-09

Never thrust the official Cooler Master rating on the back of the fan (nor anyone else disregarding their reputation, the numbers of "true honest" brands can be counted on two, perhaps three, fingers). The dB specs are on the minimum voltage, the CFM specs at maximum voltage. And even then there is "a slight difference between theory and reality".

Two such fans can be replaced by 3 120mm fans, in total a claim of 120-150 CFM for both fans wouldn't be very strange if they are both undervolted to 600-800 RPM, which is still quite good for a case. With 3 silent fans I suspect an air movement might be reached of 100-120 CFM.

boredgunner · 07-01-09

Quote:

Originally Posted by Mattb2e

Actually the 230mm fans are 150cfm, so they move much more air than a 120mm does, The only way you could get better air volume with a 120mm is by living with lots of noise. The 230mm are very quiet, I would just stick with them.

The 230mm fans used on the HAF 932 and ATCS 840 are rated at 700 RPM, 110 CFM, and 19 DBA. The 230mm fan used on the side of the Cosmos S is rated at 900 RPM and 150 CFM.

-EDIT: I'm just saying the official rating.

☢

Mattb2e · 07-01-09

Quote:

Originally Posted by boredgunner

The 230mm fans used on the HAF 932 and ATCS 840 are rated at 700 RPM, 110 CFM, and 19 DBA. The 230mm fan used on the side of the Cosmos S is rated at 900 RPM and 150 CFM.

-EDIT: I'm just saying the official rating.

☢

The rating of the fans in my case, per the part number are 150cfm p/n A23030-10CB-3DM-L1 , and runs at 900rpm

http://www.frozencpu.com/products/77...6c15s714#blank

Mattb2e · 07-01-09

Quote:

Originally Posted by Meijer

Never thrust the official Cooler Master rating on the back of the fan (nor anyone else disregarding their reputation, the numbers of "true honest" brands can be counted on two, perhaps three, fingers). The dB specs are on the minimum voltage, the CFM specs at maximum voltage. And even then there is "a slight difference between theory and reality".

Two such fans can be replaced by 3 120mm fans, in total a claim of 120-150 CFM for both fans wouldn't be very strange if they are both undervolted to 600-800 RPM, which is still quite good for a case. With 3 silent fans I suspect an air movement might be reached of 100-120 CFM.

Even if the two 230mm fans were only 110cfm at 19dba, that would total 220cfm at 19dba at the top, which would not be able to be touched by 120mm fans if you want a silent setup. Same goes for the front, only difference is you could match the cfm rating with a couple of 120mm fans, but they would most likely be louder and that would mean you need to spend more money when the stock fan works plenty good enough.

Sheira · 07-01-09

I finally ordered this case

Planning to buy two extra 120mm's on HDD cage and one on the bottom. Which fans would you recommend me?

Mattb2e · 07-01-09

Quote:

Originally Posted by Sheira

I finally ordered this case

Planning to buy two extra 120mm's on HDD cage and one on the bottom. Which fans would you recommend me?

It all depends on what your looking for, are you looking for silent fans or ones with high cfm ratings, or a balance between the two. Led, uv reactive?

Sheira · 07-01-09

Balance i guess (about the same noise as the default fans would be ideal), no leds/uv.

I know there is lots and lots of different fans.
Just throw me some general suggestion/s and i will go looking that way

As i am thinking about it, i will probably buy fan controller as well.

07-01-09	#261 (permalink)
Meijer New to Overclock.net Join Date: May 2009 Posts: 16 Rep: 3 Unique Rep: 3 Trader Rating: 0	I suggest you read this test. The Noctua's NF-P12, nor the NF-S12(A/B) don't perform as good as they are supposed to do. This has been reported so far in several extended reviews. The open-air performance of these fans comes close to the specs perhaps, but when you put a mesh/filter/anything else in front of it, the fan simply collapses. Besides, a lot of users also report a buzzing sound, where other fans would have become inaudible. The Noctua NF-P12 is one of the better Noctua fans though, and it is indeed more efficient in terms of air movement per rotation than other fans, especially on lower speeds. Above 600/700 RPM, the efficiency is reduced though. If you get these, I would undervolt them to either 7V or 5V, preferable the last option. Having said this, Scythe Gentle Typhoons are an excellent choice: very high-quality ball-bearings and very well balanced, which makes it one of the, if not the most, efficient fan when it comes to produced noise per rotation per minute. The Scythe S-Flex has a better efficiency when it comes to moved air per rotation per minute, though also more noise. Both are excellent fans and cheaper than the Noctua's. The Noctua's only come with a ton on accessoires however, like fan adapters, shock absorbers and a warranty of 6 years which might also not be too bad... Another option is that you just keep the standard fans: it's been reported the standard 230mm fans are quite good in terms of noise and air movement, especially when undervolted to 7 V for example. Just keep in mind that in the end a piece of plastic is supposed to make rotations to move a piece of air. There aren't very large differences between generally good fans. They are all good options. You should only avoid bad designs which make the fan more noisy than others, especially bearing noise and engine noise is extremely irritating. Most good fans don't have this however. Last edited by Meijer : 07-01-09 at 05:13 AM

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[Official] Cooler Master ATCS 840 Owners Club

07-01-09	#264 (permalink)
Meijer New to Overclock.net Join Date: May 2009 Posts: 16 Rep: 3 Unique Rep: 3 Trader Rating: 0	Never thrust the official Cooler Master rating on the back of the fan (nor anyone else disregarding their reputation, the numbers of "true honest" brands can be counted on two, perhaps three, fingers). The dB specs are on the minimum voltage, the CFM specs at maximum voltage. And even then there is "a slight difference between theory and reality". Two such fans can be replaced by 3 120mm fans, in total a claim of 120-150 CFM for both fans wouldn't be very strange if they are both undervolted to 600-800 RPM, which is still quite good for a case. With 3 silent fans I suspect an air movement might be reached of 100-120 CFM.

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