Edit: I didn't see your reply when I edited my last post. I dunno if talking about voltages is correct in this situation.

This is starting to change. Some of the newer motherboards offer the option of PWM or DC control on some of their headers. One example is the P5W DH. IIRC, some of the high-end Gigabyte boards also offer this.

Sorry if this sounds cynic, but have you attached a scope to the header and then measured the signals that came out of the pins at both settings? I stopped trusting what manufacturers put in manuals.

I got the impression that the difference between settings that are called like that is, that the one of them gives constant 12V on the + pin and a PWM regulating signal on the fourth pin (meant for four wire "PWM" fans), while the other setting gives a pulsed 12V signal on the + pin and nothing on the fourth pin (meant for three wire "DC" fans).

Hmm.

No I haven't. Now you have me wondering...

regarding my own experiences with arctic 3 fans in my silentium t2 case i don't think the cfm measurements in the test are correct.

as said i'm using them most of the time (regulated with a bigNG fancontroller) at voltages waaay below 5 volt (usually around 2.5 to 3 volt) and they still blow air.

at 12 volt they produce a kind of storm at the front and the back of the case.

i also don't think arctic cooling states an incorrect cfm-rating of 28 cfm at their website. the company seems realistic on other matters.

using the foam-stand must have had some detrimental effect on the output of the arctic 3 fan in the test.

I did this particular cfm measurement and was also curious about it, so I set up this test jig and tried more experimentation.

I put the anemometer right up against the exhaust side, a half inch away, and an inch away. I held the fan up in free air, in the foam stand, and at the edge of a 4" tube so the intake side was shrouded. I also tried a 1" ring of cardboard around the perimeter of the blades, to box it in like a normal axial fan.

I also compared the feel of the airflow against my hand and my face from a few inches away -- with some other fans, the Panaflo 80L, the Nexus 80. All this at 12V.

The results:

CFM measurements on the foam stand or in free air was exactly the same as before -- a little above 12cfm. It did get higher in the 4" tube, with the anemometer held about 1" away; the highest reading was around 15cfm.

By feel, it blew a touch less air than the Nexus 80 (22cfm measured), which blew less than the Panaflo 80L (30cfm measured).

Conclusions?

1) It does measure lower than expected, in free air or in our jig. The open frame may be a cause; I just don't know.
2) The fact that the cfm improved with the tube is suggestive.... but again, it's hard to interpret.
3) If our other cfm measurements are anywhere close to accurate, then I'd say there's no way I'd accept AC's 28cfm spec.

Bottom line:

Our measured cfm seems too low for the AC, but we're not sure how to get a higher/more valid reading. We may try a proper jig again just for the heck of it...

Also, I would not be 100% positive that the fans in your case are the same as the fans we tested. AC have already gone though many generations of similar looking fans.

Hehe, look at the MTBF they claim for FDB bearings .

Hello,

The AC fan is also unusual because it has only 5 blades. Since they cover a lot of area (with only small bits of "daylight" when looking straight on), this means that their pitch angle is pretty gentle -- so it is not accelerating the air as much and there are fewer blades to do the work.

ok, mike and neil and endosteel, thanks for your extensive reaction.

The NMB-MAT part numbering system is crazy. http://www.pc-cooling.ch/ Is selling what they call a "Scythe Minebea 80mm low speed fan". I don't know what it has to do with scythe, but the model number is very similar to the NMB fans you tested, and the specs for current are higher on the fan and lower on the packaging, speed, cfm and noise specs are also lower on the box



EB1 doesn't seem to be in the "part numbering system" page you linked in the article, is it the "marketing BS version" or what?

Yes, those Scythes are derived from the same basic NMB-MAT model, but I don't see why you think it's a marketing scam. It's not uncommon for a company like NMB-MAT to produce custom fans on request. And Scythe isn't even bothering to relabel; they're selling the fans on the basis of Mineba's reputation. I couldn't tell you exactly what changes scythe has requested since I haven't seen the fans in person, but this wouldn't be the first time Scythe has sold products from other companies. Scythe started as a retail store in Akihabara, and they used to distribute Arctic Cooling in Japan and the US.

Well, if you look at the sticker on the fan, it says 0.13A, but on the box we have: 0.04A, 1400rpm 16.24cfm and 17dba.

For those of you living in, or passing through Singapore, you might be pleased to know that Storage Studio in Sim Lim Square stocks Scythe fans.

I've purchased 3 Kama Flow SA0825FDB12SL fans @ SG$34.00 (~USD$22) each. They also stock the 120mm fans and other Scythe accessories.

The owners are Japanese, so that explains a lot

Their website is:

http://www.genius-asia.com.sg/

Contact/About information:

http://www.genius-asia.com.sg/eg/retailshop.htm

Here is a very recent version of the NMB-MAT 3110KL-04W-B10. Notice the small box in the lower half of the label with the code"P00". This indicates a standard nmb-mat retail version. Variations of this code indicate OEM orders, value line models, or as was suggested earlier, the scythe marketing BS version.

The blue label nmb-mat fans in the spcr review are most likely aged surplus and "P02" is probably a dell or compaq code. At least in the 92mm fan review, spcr lists the supplier.

By the way, this is a really quiet fan.


NMB-MAT 3110KL-04W-B10
Purchased from: Digikey
Price: $11.13

Here are some of the latest 80mm nmb-mat (panaflo) retail models. The first one is an L1-AZ. The "Z" indicates the closed corner option and is a good substitute for the L1-A as it is always in short supply.


FBA08A12L-1AZ
Purchased from: Digikey
Price: $8.25




FBA08A12M-1A
Purchased from: Digikey
Price: $8.25