Viewing page 3 of 6 pages.
Previous 1 2 3 4 5 6 Next
SILENX IXTREMA PRO IXP-74-11
Ambient noise at the time of testing was 18 dBA.
| Brand |
SilenX |
Power Rating |
0.16A / 1.92W |
| Manufacturer |
? |
Airflow Rating |
43 CFM |
| Model Number |
IXP-74-11 |
RPM Rating |
1,100 RPM |
| Retail Availability |
Yes |
Noise Rating |
11 dBA |
| Bearing Type |
Hybrid Immersion |
Header Type |
3-pin & Molex Adapter |
| Hub Size |
1.29" |
Starting Voltage |
2.5V |
| Frame Size |
120 x 120 x 25 mm |
Number of Samples |
2 |
|
Our thanks to Anitec
Computer Technology for supplying these samples.
|
|
Voltage
|
Noise
|
RPM
|
CFM
|
Power
|
|
12V
|
26 dBA@1m
|
1140 RPM
|
35 CFM
|
2.80W
|
|
9V
|
22 dBA@1m
|
960 RPM
|
29 CFM
|
2.13W
|
|
7V
|
20 dBA@1m
|
820 RPM
|
25 CFM
|
1.72W
|
|
5V
|
~19 dBA@1m
|
660 RPM
|
19 CFM
|
1.27W
|
|
@25 CFM (7.0V)
|
20 dBA@1m
|
820 RPM
|
25 CFM
|
1.72W
|
May 5, 2008
The updated airflow results here are the result of improvements
in our testing procedures. They are more accurate than the original results
above, but they are not directly comparable. Please compare these only with
fan reviews published after May 5, 2008 — or ones that have updated
results published in a box like this one. |
|
12V
|
26 dBA@1m
|
1140 RPM
|
35 CFM
|
2.80W
|
|
9V
|
22 dBA@1m
|
960 RPM
|
27 CFM
|
2.13W
|
|
7V
|
20 dBA@1m
|
820 RPM
|
23 CFM
|
1.72W
|
|
5V
|
~19 dBA@1m
|
660 RPM
|
19 CFM
|
1.27W
|
|
@20 CFM (5.6V)
|
20 dBA@1m
|
700 RPM
|
20 CFM
|
1.41W
|
May 5, 2008
The SilenX Ixtrema Pro was one of the few fans whose results went
up when we retested all of our fans. In light of the new results, it
now boasts one of the best airflow-per-rotation ratios that we've seen. It's
unfortunate tendancy to resonate still hinders it, but it may be worth a second
look. Please evaluate the new results carefully.
A SilenX at last. A "proper" SilenX, not an
obscure 80mm model. Those of you who aren't regular readers are probably
wondering what the big deal is. To summarize a very long story:
- A SilenX spokesman was caught shilling his product by carrying on a conversation
with himself on SPCR's forums, reregistering himself several times after his
fraudulent activities were exposed by SPCR staff.
- SilenX' specifications are notoriously exaggerated, especially where noise
is concerned.
- Thanks to widespread distribution and aggressive marketing (see point 2.),
SilenX fans have a reputation for being quiet — but not on SPCR
- For a very long time, in part because of point 1., SPCR had never "officially"
reviewed a SilenX product.
All of this has been water under the bridge for some time, but a reputation
once earned is hard to get rid of. And, every month or so, someone new asks
why SPCR hasn't reviewed / approved any SilenX fans, and the whole thing gets
dragged out of the mud again.
All of this is really just a very long way of saying one thing: SilenX carries
baggage at SPCR. And so, by popular demand, here is an "official"
SPCR look at one of SilenX' current 120mm fans.
Perhaps because SPCR has been so hard on them in the past, SilenX has gone
out of their way to prove the legitimacy of their noise specifications. They
are one of the very few manufacturers that specifies a measurement distance
along with their noise specification: "Measurements are taken in an
anechoic chamber from a distance of 1m along each of the 3 axes and a mean is
calculated from the readings". We've been talking ourselves blue in
the face about the importance of measurement distance, and SilenX is one of
the few manufacturers that seems to have listened.
Unfortunately, while SilenX appears to be doing everything right, we still
can't reconcile our 26 dBA@1m reading with SilenX' 11 dBA@1m. That's
not a small difference. It's hard to write that off as measurement variance,
even allowing for the fact that SPCR doesn't have access to an ultra-quiet anechoic
chamber. Given how far above ambient our own measurement is, SilenX' 11 dBA
noise spec just doesn't wash.
Quibbles with specifications aside, the SilenX doesn't sound too bad. It's
probably smooth enough for most casual users, though enthusiasts will be less
pleased. The fancy "metallic" plastic used for the frame may look
flashy, but it's terrible for sound. Lightweight and brittle, the material picks
up fan vibration easily and audibly, giving the fan a highly resonant character.
At slower speeds, the resonance manifests itself as a deep buzz or growl, while
at higher speeds it's more like a pure tone. The resonance prevents what is
an otherwise low-noise fan from ever becoming truly inaudible, even at 5V.
Silicone grommets to help control vibration resonance.
It's unfortunate that SilenX chose such a poor quality material, since they've
done several other things right. Most significantly, the retail package comes
with four silicone grommets that are intended to deal with the issue just raised:
Resonance. Such grommets can help prevent the transfer of vibration to the case,
but they do nothing for the resonance in the fan itself.
It's also worth pointing out that SilenX has made an effort to force as much
airflow as possible out of the Ixtrema Pro. The center hub is unusually small,
apparently "for reduced air turbulence" and to allow slightly more
air to pass through the frame. As a result, the fan blades appear unusually
long and scooped. SilenX' marketing material claims that this gives the fan
better pressure characteristics, but how much so is difficult to say. Our airflow
measurements did not uncover anything particularly special about the Ixtrema
Pro's airflow characteristics... but we are unable to measure the effects of
pressure.
All in all, the Ixtrema Pro is an interesting fan that may be worth experimenting
with. Although it's noise character is not perfect, it may be good enough to
work with while learning about what kind of airflow is produced by its unusual
blade design.
Noise Recording
ARCTIC COOLING ARCTIC FAN 12L
Ambient noise at the time of testing was 18 dBA.
| Brand |
Arctic
Cooling |
Power Rating |
0.15A |
| Manufacturer |
Arctic Cooling? |
Airflow Rating |
37 CFM |
| Model Number |
Arctic Fan 12L |
RPM Rating |
1,000 RPM |
| Retail Availability |
Yes |
Noise Rating |
20.0 dBA / 0.3 Sone |
| Bearing Type |
FDB |
Header Type |
3-pin |
| Hub Size |
1.85" |
Starting Voltage |
5.3V |
| Frame Size |
120 x 120 x 25 mm |
Number of Samples |
3 |
|
Voltage
|
Noise
|
RPM
|
CFM
|
Power
|
|
12V
|
23 dBA@1m
|
1040 RPM
|
28 CFM
|
0.61W
|
|
9V
|
20 dBA@1m
|
820 RPM
|
20 CFM
|
0.49W
|
|
7V
|
~18 dBA@1m
|
650 RPM
|
17 CFM
|
0.41W
|
|
5V
|
<18 dBA@1m
|
480 RPM
|
11 CFM
|
0.35W
|
|
@25 CFM (11.0V)
|
21 dBA@1m
|
970 RPM
|
25 CFM
|
0.57W
|
May 5, 2008
The updated airflow results here are the result of improvements
in our testing procedures. They are more accurate than the original results
above, but they are not directly comparable. Please compare these only with
fan reviews published after May 5, 2008 — or ones that have updated
results published in a box like this one. |
|
12V
|
23 dBA@1m
|
1040 RPM
|
26 CFM
|
0.61W
|
|
9V
|
20 dBA@1m
|
820 RPM
|
21 CFM
|
0.49W
|
|
7V
|
~18 dBA@1m
|
650 RPM
|
16 CFM
|
0.41W
|
|
5V
|
<18 dBA@1m
|
480 RPM
|
10 CFM
|
0.35W
|
|
@20 CFM (8.8V)
|
20 dBA@1m
|
810 RPM
|
20 CFM
|
0.47W
|
May 5, 2008
The questionable airflow results for Arctic Cooling's fans was one
of the major reason for developing our new methodology. We are now much more
confident in the results for this fan — and its results move it up in the
rankings as well. Unfortunately, the change only brings it up to the middle
of the pack — it's still not one of our favorite fans. Questions about
its ability to provide good air pressure remain.
Arctic Cooling has established itself as a tough little company with a reputation
for engineering inexpensive but elegant products. They were one of the first
companies to take noise seriously as a design issue, and some of their past
products have become favorites on SPCR.
Arctic Cooling has been experimenting with "frameless" fans for a
long while — first on their heatsinks, and then later as independent models.
The idea is to reduce air turbulence (and its corresponding noise), and, in
general, Arctic Cooling has done a good job of making quiet fans in the past.
The most recent incarnation of these fans retains the open design and adds
silicone grommets that are intended to reduce the amount of vibration conducted
through the frame to the case. The motor assembly and the frame are actually
separate pieces, held together by four silicone mounting posts. The silicone
is soft and pliable, and should do an excellent job of reducing vibration.
The entire motor assembly is soft-mounted with silicone grommets.
Measuring the Arctic Fan 12L fairly was a challenge; its unconventional design
caused serious issues with our original technique for measuring airflow. In
fact, the fan's unusual characteristics were a factor in our recent decision
to update our airflow testing
methodology, as our previous technique produced results that were unrealistically
low. Our new system of measurement brought the Arctic Fan 12L back in line with
our expectations, though it still seemed to produce slightly less airflow overall.
However, the difference was no more than 5~10% — not enough to worry about
from a thermal perspective.
The small disadvantage in airflow proved to be a larger disadvantage when the
fan was compared to other fans at 25 CFM. That 5~10% difference was enough to
make the Arctic Fan 12L clearly audible at 25 CFM where other fans managed to
disappear, since the Arctic Fan had to spin faster to produce the same amount
of airflow. Were it not for this disadvantage, the Arctic Fan would be worthy
of recommendation, but unfortunately, it doesn't quite keep up.
The noise character was a low growling hum that got smoother as the fan speeded
up. The fan was inaudible from a distance of one meter below about 6V, but moving
closer the sound became clearly audible and was quite rough-sounding. Above
this level, the noise became smoother and more pleasant to listen to, but it
also increased in volume. It was difficult to find a balance between low volume
and good noise character.
The silicone grommets surprised us in that they didn't seem to do much to stop
vibration. In fact, the Arctic Fan had more vibration that most of the other
fans. Ironically, this is likely a result of the frameless design. Generally,
fans with heavy, solid frames exhibit less vibration because they have more
inertia to resist motion. With such a lightweight frame, the Arctic Fan literally
hummed with motion, the grommets moving along with everything else. It's possible
the fan would perform better when hard-mounted to a solid case, but our free-air
tests weren't encouraging.
Noise Recording
JUMP TO:
| Help support this site, buy from one of our affiliate retailers! |
|
