Necessity for case fans

[pinnerite]

The four 6 cm case fans (2 in and 2 out) on opposite sides of the case of my HTPC had become noisy.

I replaced them with ball-bearing jobs from Currys PC World. They turned out to be even noisier.

The processor is an Intel i3-3220, a relatively low power device, perfect for its role.

I disconnected the four case fans and powered up the machine. Silent as the grave but is it safe?

I have been monitoring its cpu temerature from another machine. For the last half an hour it has been relatively stable with one core approx. 38 degrees C, the other 42 degrees C.

It had been running for several hours.

So, would it be safe to remove the fans completely?
It would improve the airflow from the processor fan.

[Paul]

Post by pinnerite
The four 6 cm case fans (2 in and 2 out) on opposite sides of the case of my HTPC had become noisy.
I replaced them with ball-bearing jobs from Currys PC World. They turned out to be even noisier.
The processor is an Intel i3-3220, a relatively low power device, perfect for its role.
I disconnected the four case fans and powered up the machine. Silent as the grave but is it safe?
I have been monitoring its cpu temerature from another machine. For the last half an hour it has been relatively stable with one core approx. 38 degrees C, the other 42 degrees C.
It had been running for several hours.
So, would it be safe to remove the fans completely?
It would improve the airflow from the processor fan.

Check hard drive temperature. See what product limit is.

Modern motherboard VCore circuits use exceptionally small
heatsinks. You might stick a finger on that area and
see if your finger gets burned. It's not that the circuit
has a lot of waste heat - but it does typically need
some heatsinking.

There aren't a lot of branded fans to choose from.
You could try Noctua, as at least those, the evidence
is that they last. Be wary of these, as they're available
in 5V and 12V version and you want the 12V one. This is the
four pin one, suitable for modern PCs with four pin PWM headers.
Note the MTBF of 150000 hours!

https://www.amazon.co.uk/Noctua-NF-A6x25-PWM-Premium-Quiet/dp/B00VXTANZ4

Ball bearing fans are 3dB louder than sleeve bearing fans.
There are also FDB motors, which don't have ball bearings
and rely on oil pumped under pressure along the rotating
surface. I suspect the Noctua is FDB.

You can check the fan headers on the HTPC PCB and see
if they're four pin or three pin. A four pin header
uses PWM control of fan speed. A three pin header
uses voltage control (effectively a PWM circuit
implemented on the motherboard by the motherboard
maker, costs them about $1 per circuit to do this,
so not popular).

A four pin connector can "hang over" a three pin mobo
header, but by doing so, the fan runs full speed
(because the PWM pin which is not connected, floats
to the logic 1 state or "100% PWM").

Four Pin +12V GND RPM_out PWM_in

Three Pin +12V GND RPM_out

You could switch from a four fan pattern to a two
fan pattern. For example, this is noisy for no
good reason.

<== Fan1 Fan2 <==

<== Fan3 Fan4 <==

That could be replaced with... push-into-case only.

<== Fan2 <==

<== Fan4 <==

Try a pair of Noctua, and see if you've got some
four pin headers (other than the CPU one) for the
job. As far as I know, the PWM signals for this are
"just about free" from an implementation cost perspective.
Unlike the voltage control method on the three pin,
where only HP put that on all three headers on the mobo.

Four pin PWM fans, are only to be fed +12V, and then
the fourth pin modulates the voltage. Three pin fans,
the fan does not mind running at +7V (voltage control).
The four pin version must be fed 12V, to avoid
compromising the MOSFET inside the hub. You have to
know what kind of headers you've got, what controls
they have, to make the best of a bad situation on
connector choices (three or four pin). If would be
nice if your motherboard had all four pin ones, as
there's no additional cost for them to do that
(as long as there are enough PWM pins on the chipset).

You can also get rheobus controllers of various
sorts, for setting fan speed. But that's an esoteric
topic, with some of the controllers coming from
Germany, and supply of them being uncertain. If the
rheobus is a voltage control type (three pin), then
you'd want to buy three pin fans to match. That Noctua
60mm is available in both flavors. There are
four products total

5V four pin
5V three pin (voltage controlled, cheap rheobus or Zalman Fanmate)
12V four pin
12V three pin (voltage controlled, cheap rheobus or Zalman Fanmate)

Fanmates are good, but we never really know for sure whether
Zalman is an actual live company or not (they got flim-flammed
years ago, and their financial health was/is an unknown).

Example of a Fanmate, the first reference I could find.
Amazon UK didn't list this. You could use this with a
Noctua "12V three pin" and then would not need to worry
about software control of fan speed. (This allows static
control of fan speed, set and forget. It's just a pot, not
some intelligent device.)

https://www.amazon.ca/Zalman-Fan-Speed-Controller-FANMATE-2/dp/B000292DO0

HTH,
Paul

[pinnerite]

On Mon, 10 May 2021 18:01:40 -0400

Post by Paul

Post by pinnerite
The four 6 cm case fans (2 in and 2 out) on opposite sides of the case of my HTPC had become noisy.
I replaced them with ball-bearing jobs from Currys PC World. They turned out to be even noisier.
The processor is an Intel i3-3220, a relatively low power device, perfect for its role.
I disconnected the four case fans and powered up the machine. Silent as the grave but is it safe?
I have been monitoring its cpu temerature from another machine. For the last half an hour it has been relatively stable with one core approx. 38 degrees C, the other 42 degrees C.
It had been running for several hours.
So, would it be safe to remove the fans completely?
It would improve the airflow from the processor fan.

Check hard drive temperature. See what product limit is.
Modern motherboard VCore circuits use exceptionally small
heatsinks. You might stick a finger on that area and
see if your finger gets burned. It's not that the circuit
has a lot of waste heat - but it does typically need
some heatsinking.
There aren't a lot of branded fans to choose from.
You could try Noctua, as at least those, the evidence
is that they last. Be wary of these, as they're available
in 5V and 12V version and you want the 12V one. This is the
four pin one, suitable for modern PCs with four pin PWM headers.
Note the MTBF of 150000 hours!
https://www.amazon.co.uk/Noctua-NF-A6x25-PWM-Premium-Quiet/dp/B00VXTANZ4
Ball bearing fans are 3dB louder than sleeve bearing fans.
There are also FDB motors, which don't have ball bearings
and rely on oil pumped under pressure along the rotating
surface. I suspect the Noctua is FDB.
You can check the fan headers on the HTPC PCB and see
if they're four pin or three pin. A four pin header
uses PWM control of fan speed. A three pin header
uses voltage control (effectively a PWM circuit
implemented on the motherboard by the motherboard
maker, costs them about $1 per circuit to do this,
so not popular).
A four pin connector can "hang over" a three pin mobo
header, but by doing so, the fan runs full speed
(because the PWM pin which is not connected, floats
to the logic 1 state or "100% PWM").
Four Pin +12V GND RPM_out PWM_in
Three Pin +12V GND RPM_out
You could switch from a four fan pattern to a two
fan pattern. For example, this is noisy for no
good reason.
<== Fan1 Fan2 <==
<== Fan3 Fan4 <==
That could be replaced with... push-into-case only.
<== Fan2 <==
<== Fan4 <==
Try a pair of Noctua, and see if you've got some
four pin headers (other than the CPU one) for the
job. As far as I know, the PWM signals for this are
"just about free" from an implementation cost perspective.
Unlike the voltage control method on the three pin,
where only HP put that on all three headers on the mobo.
Four pin PWM fans, are only to be fed +12V, and then
the fourth pin modulates the voltage. Three pin fans,
the fan does not mind running at +7V (voltage control).
The four pin version must be fed 12V, to avoid
compromising the MOSFET inside the hub. You have to
know what kind of headers you've got, what controls
they have, to make the best of a bad situation on
connector choices (three or four pin). If would be
nice if your motherboard had all four pin ones, as
there's no additional cost for them to do that
(as long as there are enough PWM pins on the chipset).
You can also get rheobus controllers of various
sorts, for setting fan speed. But that's an esoteric
topic, with some of the controllers coming from
Germany, and supply of them being uncertain. If the
rheobus is a voltage control type (three pin), then
you'd want to buy three pin fans to match. That Noctua
60mm is available in both flavors. There are
four products total
5V four pin
5V three pin (voltage controlled, cheap rheobus or Zalman Fanmate)
12V four pin
12V three pin (voltage controlled, cheap rheobus or Zalman Fanmate)
Fanmates are good, but we never really know for sure whether
Zalman is an actual live company or not (they got flim-flammed
years ago, and their financial health was/is an unknown).
Example of a Fanmate, the first reference I could find.
Amazon UK didn't list this. You could use this with a
Noctua "12V three pin" and then would not need to worry
about software control of fan speed. (This allows static
control of fan speed, set and forget. It's just a pot, not
some intelligent device.)
https://www.amazon.ca/Zalman-Fan-Speed-Controller-FANMATE-2/dp/B000292DO0
HTH,
Paul

Thank you for going to so much trouble.

Overnight the temperature of both cores had dropped a few degrees and have maintained that all day. The hard drive is never driven hard but I will check it as recommended.

Regards, Alan

[pinnerite]

On Tue, 11 May 2021 15:38:50 +0100

Post by pinnerite
On Mon, 10 May 2021 18:01:40 -0400

Post by Paul

Post by pinnerite
The four 6 cm case fans (2 in and 2 out) on opposite sides of the case of my HTPC had become noisy.
I replaced them with ball-bearing jobs from Currys PC World. They turned out to be even noisier.
The processor is an Intel i3-3220, a relatively low power device, perfect for its role.
I disconnected the four case fans and powered up the machine. Silent as the grave but is it safe?
I have been monitoring its cpu temerature from another machine. For the last half an hour it has been relatively stable with one core approx. 38 degrees C, the other 42 degrees C.
It had been running for several hours.
So, would it be safe to remove the fans completely?
It would improve the airflow from the processor fan.

Check hard drive temperature. See what product limit is.
Modern motherboard VCore circuits use exceptionally small
heatsinks. You might stick a finger on that area and
see if your finger gets burned. It's not that the circuit
has a lot of waste heat - but it does typically need
some heatsinking.
There aren't a lot of branded fans to choose from.
You could try Noctua, as at least those, the evidence
is that they last. Be wary of these, as they're available
in 5V and 12V version and you want the 12V one. This is the
four pin one, suitable for modern PCs with four pin PWM headers.
Note the MTBF of 150000 hours!
https://www.amazon.co.uk/Noctua-NF-A6x25-PWM-Premium-Quiet/dp/B00VXTANZ4
Ball bearing fans are 3dB louder than sleeve bearing fans.
There are also FDB motors, which don't have ball bearings
and rely on oil pumped under pressure along the rotating
surface. I suspect the Noctua is FDB.
You can check the fan headers on the HTPC PCB and see
if they're four pin or three pin. A four pin header
uses PWM control of fan speed. A three pin header
uses voltage control (effectively a PWM circuit
implemented on the motherboard by the motherboard
maker, costs them about $1 per circuit to do this,
so not popular).
A four pin connector can "hang over" a three pin mobo
header, but by doing so, the fan runs full speed
(because the PWM pin which is not connected, floats
to the logic 1 state or "100% PWM").
Four Pin +12V GND RPM_out PWM_in
Three Pin +12V GND RPM_out
You could switch from a four fan pattern to a two
fan pattern. For example, this is noisy for no
good reason.
<== Fan1 Fan2 <==
<== Fan3 Fan4 <==
That could be replaced with... push-into-case only.
<== Fan2 <==
<== Fan4 <==
Try a pair of Noctua, and see if you've got some
four pin headers (other than the CPU one) for the
job. As far as I know, the PWM signals for this are
"just about free" from an implementation cost perspective.
Unlike the voltage control method on the three pin,
where only HP put that on all three headers on the mobo.
Four pin PWM fans, are only to be fed +12V, and then
the fourth pin modulates the voltage. Three pin fans,
the fan does not mind running at +7V (voltage control).
The four pin version must be fed 12V, to avoid
compromising the MOSFET inside the hub. You have to
know what kind of headers you've got, what controls
they have, to make the best of a bad situation on
connector choices (three or four pin). If would be
nice if your motherboard had all four pin ones, as
there's no additional cost for them to do that
(as long as there are enough PWM pins on the chipset).
You can also get rheobus controllers of various
sorts, for setting fan speed. But that's an esoteric
topic, with some of the controllers coming from
Germany, and supply of them being uncertain. If the
rheobus is a voltage control type (three pin), then
you'd want to buy three pin fans to match. That Noctua
60mm is available in both flavors. There are
four products total
5V four pin
5V three pin (voltage controlled, cheap rheobus or Zalman Fanmate)
12V four pin
12V three pin (voltage controlled, cheap rheobus or Zalman Fanmate)
Fanmates are good, but we never really know for sure whether
Zalman is an actual live company or not (they got flim-flammed
years ago, and their financial health was/is an unknown).
Example of a Fanmate, the first reference I could find.
Amazon UK didn't list this. You could use this with a
Noctua "12V three pin" and then would not need to worry
about software control of fan speed. (This allows static
control of fan speed, set and forget. It's just a pot, not
some intelligent device.)
https://www.amazon.ca/Zalman-Fan-Speed-Controller-FANMATE-2/dp/B000292DO0
HTH,
Paul

Thank you for going to so much trouble.
Overnight the temperature of both cores had dropped a few degrees and have
maintained that all day. The hard drive is never driven hard but I will check it > as recommended.
Regards, Alan

With the case top off, the recorded cpu temperatures are lower during the day and higher at night. A variance of between 4 and 6 degrees C but not material.
Removing the noisy side fans has increased the air flow, in part because the removal of their power cables released more space.

The hard drive is running at 32 degress C. Half the manufacturers rating.

An unexpected irritation was the processor's cooler fan starting to exhibit fluctuating speed. Luckily I was able to locate an identical replacement. It arrives tomorrow!

Regards, Alan

-
Mint 20.04, kernel 5.4.0-42-generic, Cinnamon 4.6.7
running on an AMD Phenom II X4 Black edition processor with 8GB of DRAM.

[wicklowham]

Post by Paul

Post by pinnerite
The four 6 cm case fans (2 in and 2 out) on opposite sides of the case
of my HTPC had become noisy.
I replaced them with ball-bearing jobs from Currys PC World. They
turned out to be even noisier.
The processor is an Intel i3-3220, a relatively low power device, perfect for its role.
I disconnected the four case fans and powered up the machine. Silent
as the grave but is it safe?
I have been monitoring its cpu temerature from another machine. For
the last half an hour it has been relatively stable with one core
approx. 38 degrees C, the other 42 degrees C.
It had been running for several hours.
So, would it be safe to remove the fans completely?
It would improve the airflow from the processor fan.

Check hard drive temperature. See what product limit is.
Modern motherboard VCore circuits use exceptionally small
heatsinks. You might stick a finger on that area and
see if your finger gets burned. It's not that the circuit
has a lot of waste heat - but it does typically need
some heatsinking.
There aren't a lot of branded fans to choose from.
You could try Noctua, as at least those, the evidence
is that they last. Be wary of these, as they're available
in 5V and 12V version and you want the 12V one. This is the
four pin one, suitable for modern PCs with four pin PWM headers.
Note the MTBF of 150000 hours!
https://www.amazon.co.uk/Noctua-NF-A6x25-PWM-Premium-Quiet/dp/B00VXTANZ4
Ball bearing fans are 3dB louder than sleeve bearing fans.
There are also FDB motors, which don't have ball bearings
and rely on oil pumped under pressure along the rotating
surface. I suspect the Noctua is FDB.
You can check the fan headers on the HTPC PCB and see
if they're four pin or three pin. A four pin header
uses PWM control of fan speed. A three pin header
uses voltage control (effectively a PWM circuit
implemented on the motherboard by the motherboard
maker, costs them about $1 per circuit to do this,
so not popular).
A four pin connector can "hang over" a three pin mobo
header, but by doing so, the fan runs full speed
(because the PWM pin which is not connected, floats
to the logic 1 state or "100% PWM").
   Four Pin   +12V GND RPM_out PWM_in
   Three Pin  +12V GND RPM_out
You could switch from a four fan pattern to a two
fan pattern. For example, this is noisy for no
good reason.
      <== Fan1        Fan2 <==
      <== Fan3        Fan4 <==
That could be replaced with... push-into-case only.
      <==             Fan2 <==
      <==             Fan4 <==
Try a pair of Noctua, and see if you've got some
four pin headers (other than the CPU one) for the
job. As far as I know, the PWM signals for this are
"just about free" from an implementation cost perspective.
Unlike the voltage control method on the three pin,
where only HP put that on all three headers on the mobo.
Four pin PWM fans, are only to be fed +12V, and then
the fourth pin modulates the voltage. Three pin fans,
the fan does not mind running at +7V (voltage control).
The four pin version must be fed 12V, to avoid
compromising the MOSFET inside the hub. You have to
know what kind of headers you've got, what controls
they have, to make the best of a bad situation on
connector choices (three or four pin). If would be
nice if your motherboard had all four pin ones, as
there's no additional cost for them to do that
(as long as there are enough PWM pins on the chipset).
You can also get rheobus controllers of various
sorts, for setting fan speed. But that's an esoteric
topic, with some of the controllers coming from
Germany, and supply of them being uncertain. If the
rheobus is a voltage control type (three pin), then
you'd want to buy three pin fans to match. That Noctua
60mm is available in both flavors. There are
four products total
   5V four pin
   5V three pin  (voltage controlled, cheap rheobus or Zalman Fanmate)
  12V four pin
  12V three pin  (voltage controlled, cheap rheobus or Zalman Fanmate)
Fanmates are good, but we never really know for sure whether
Zalman is an actual live company or not (they got flim-flammed
years ago, and their financial health was/is an unknown).
Example of a Fanmate, the first reference I could find.
Amazon UK didn't list this. You could use this with a
Noctua  "12V three pin" and then would not need to worry
about software control of fan speed. (This allows static
control of fan speed, set and forget. It's just a pot, not
some intelligent device.)
https://www.amazon.ca/Zalman-Fan-Speed-Controller-FANMATE-2/dp/B000292DO0
HTH,
   Paul

=============
About a year + ago I needed to replace a Dell Pentium 4 desktop PC from
AD2005 . Its replacement is a fanless miniPC with a 2 core i7 CPU ,8GB
RAM and a 256GB SSD . Its power supply is 12V-DC ,45 Watts max
I came with 2 antennas for built-in WiFi
I am very pleased with this "completely silent" machine sourced from a
Chinese on-line supplier.

If my 10 years old other desktop PC with a first generation i7 CPU , 8GB
RAM , 5 years ago fitted with a 256GB SSD.....still running flawlessly
with its multiple original (moderate noise) fans , ever needs
replacement , I again would go for a fanless miniPC with its heatsink
type of enclosure

This 10 years old desktop PC was ordered as a "barebone" machine having
a Gigabyte motherboard .

All my machines run Linux Mint.

Frank in County Wicklow - Ireland