Archived from groups: alt.comp.hardware.overclocking,alt.comp.periphs.mainboard.asus (
More info?)
In short...
o No
o The signal on that pin is Locked-Rotor (1A) and not Tacho signal (1BX)
---- Not commonly readable on PCs
---- Commonly readable/used/required on Apple/SUN/SGI/DEC-Alpha
o Only a few Panaflo are available with 1BX option code
---- 60mm in H noise-spec, 80mm in M noise-spec, 120mm in H noise-spec
---- 92mm in L noise-spec
o The 1BX option code uses a different PCB & motor-ic
---- the 1A motor-ic is generally slightly quieter for silence-addicts
-------- it uses soft-edged microprocessor switching for low-noise
---- the 1BX motor-ic has the caveat of higher switching noise evident
-------- however some applications will not run without a tacho signal
Tacho signal on tier-1 fans is somewhat moot - the fan has an L10 figure,
field-data confirmed, that exceeds the typical life of the equipment it goes in.
In full...
o Panasonic Panaflo part numbers describe the actual specs of the fan
---- same for all fan makers, just a matter of knowing how they work
o Note that OEM (integrated into product) codes may differ
---- codes may be the OEM codes, or equivalent field-replaceable units
---- odd sizes are possible, eg, 70mm, 100mm, 110mm but very rare
For 60-120mm fans, taking FBA08A12L1A:
o FBA = Non-Augmented Flow Tubeaxial Fan (ie, not FBL, FBK, FBZ)
o 08A = 80x80x25mm, 08T = 80x80x15mm etc
o 12 = 12V DC, 24 = 24V DC
o L = Low Noise Spec (M H U are available, OEM can use others)
---- eventually you will see an S spec below L, but not for some time
o 1A = option code
---- 1A = Locked-Rotor Signal on 3rd "S" marked pin
-------- 1BS, 1J, 1AZ, 1BO similarly don't provide tacho output
-------- 1AZ is 1A with solid corners for more rigid blade-to-housing gap
---- 1BX = Tacho-RPM Signal on 3rd "S" marked pin
-------- 1CX is available, but relatively uncommon
The 40mm Panaflo don't have commonly have such option codes.
For Papst the tacho signal is designated by a /2 on the fan model code
o Example, an 8412NGML in tacho-signal form is 8412NGML/2
o Only a few Papst fans are provided with the signal at retail level
o Note than OEM options are broad, such as /9, /14 codes
---- so connect only a /2 fan to a PC - other codes are not compatible
For NMB the tacho signal is designated by TWO option codes
o Taking NMB 3110KL-04W-B10-A00, the last TWO codes matter
---- B10 is your noise level AND an option code
---- A00 is another option code
o For tacho signal, BOTH the B code & A code are modified
---- the B code gets a 9 added, the A code must be 50-100
---- So NMB 3110KL-04W-B19-A49 is NOT tacho
---- So NMB 3110KL-04W-B19-A99 IS with tacho signal
o Other option codes are possible in the B option code
---- B66, B16, B23 etc
---- typically these are OEM spec fans & noise-level may vary
For example, Dell use a B66 spec fan & B86 fan on their topline
Dimension computers - both have extremely high airflow figures.
Dell implements a remote temperature control system - so allowing
the same fan to be fitted in the PC be it in non-HVAC Saudi or in
freezing North Pole environments, the speed simply adapts.
Eventually such temp variation will be dropped as it has time latency,
thermal latency, hysterisis and often poor matching = acoustic noise.
Instead the fan speed will be regulated to current draw via either the
CPU, or current supply via the PSU - so instant response. That
avoids the common problem of a macro noise/thermal solution from
a temp-controlled fan still having some areas running hot either when
tested as a physical prototype or thermal CFD model in Flotherm.
Tier-1 makers are generally integration - and so design options to suit.
NMB do about 200M, >45% of the global market, with only a very
small number going into retail which is a disliked channel as availability
of replacement options there disintermediates out silly overpriced spares
from manufacturers. Sometimes proprietarisation can be used to stop
a substitute fan, either at simple level (Apple reverse the pins) or more
complex level (custom 2-speed control & feedback with no-boot).
Dec Alpha's will not boot without a 1A signal fan re "fan turning".
Tacho fans are often available only on specific models, and NMB in
general don't have any tacho models available to retail. You can order
them, but it's pay up-front, 16-26wk waiting period subject to JIT
factory scheduling, and min orders quantities which can be 50k units.
That's for tier-1 fan makers, lower tiers choose different segments and
may put OEM tacho models out into retail distribution more often. Most
makers only make a tiny fraction of their available range (eg, ADDA have
a simply vast range but only make a tiny part of it). Others, like EBM-Papst
offer a very large range of fan sizes - and make all of them, but only a few
are available with tacho signal. Depends on the market demands re economics.
Eventually the tier-1 fans will be programmable - you choose what you want
by non-contact programming or signal down a lead (like AMD program their
XPs according to requirements or yield capability). That is in the future, EBM-Papst
are likely to be the first although NMB may offer it first. I doubt it will be available
to end-users, it may be for distributor profit/convenience/availability instead. So
for end-users there would be a benefit, as well as to their ears.
--
Dorothy Bradbury
www.stores.ebay.co.uk/panaflofan for quiet Panaflo fans & other items
http://homepage.ntlworld.com/dorothy.bradbury/panaflo.htm (Direct)
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