Chassis fan speed control question

  • Thread starter Thread starter Imer Satz
  • Start date Start date
I

Imer Satz

My rig:

-Cooler Master Praetorian chassis, with two 80mm front intake fans, one 80mm
top intake fan and one 80mm rear exhaust fan
-Enermax Noisetaker 375W PSU, with one 90mm intake fan and one 80mm exhaust
fan
-Intel 2.6C CPU with OEM heatsink and fan
-Asus P4C800-E Deluxe motherboard, FSB at 250

The system is in a room that's about 16C. At idle, the BIOS reports the
motherboard at 18C and the CPU at 22C. Obviously, cooling is not my problem.

The aluminum case of the Praetorian vibrates like a jet engine, and I'm sure
the cause is the intake fans. If I pop a side panel a bit, the noise
subsides somewhat. It would seem I'd want to throttle the intake fans, which
I believe are pushing against too much resistance, yet motherboard control
is limited to the chassis exhaust fan and PSU fans, which I would expect
only to exacerbate the problem. Cooler Master makes two-state,
thermostatically controlled fans, but I don't believe they installed them in
this chassis.

I'm aware of add-on products, like the Vantec Nexus, but wonder first what
the inherent design solution to this problem might be? My first thought is
to install two-stage input fans and apply vibration dampeners to the side
panels. Would you concur?

Thanks.
 
Imer Satz said:
My rig:

-Cooler Master Praetorian chassis, with two 80mm front intake fans, one 80mm
top intake fan and one 80mm rear exhaust fan
-Enermax Noisetaker 375W PSU, with one 90mm intake fan and one 80mm exhaust
fan
-Intel 2.6C CPU with OEM heatsink and fan
-Asus P4C800-E Deluxe motherboard, FSB at 250

The system is in a room that's about 16C. At idle, the BIOS reports the
motherboard at 18C and the CPU at 22C. Obviously, cooling is not my problem.

The aluminum case of the Praetorian vibrates like a jet engine, and I'm sure
the cause is the intake fans. If I pop a side panel a bit, the noise
subsides somewhat. It would seem I'd want to throttle the intake fans, which
I believe are pushing against too much resistance, yet motherboard control
is limited to the chassis exhaust fan and PSU fans, which I would expect
only to exacerbate the problem. Cooler Master makes two-state,
thermostatically controlled fans, but I don't believe they installed them in
this chassis.

I'm aware of add-on products, like the Vantec Nexus, but wonder first what
the inherent design solution to this problem might be? My first thought is
to install two-stage input fans and apply vibration dampeners to the side
panels. Would you concur?
Click to expand...

Is the top fan really intake and not a 'blow hole' exhaust? At the
moment it would appear that the intake/exhaust is far from balanced,
however, as your temperatures are very low - particularly the room
temperature :-() try disconnecting one or both of the intake fans - if
the temperatures start to climb significantly you may need to remove the
fan(s) from the inlet hole(s) to improve the airflow. If you decide
that the intake fans are essential you may want to look at isolator
mounts for the fans (I use them on the single 120mm fan in my virtually
silent kit) - if you have not seen them before have a look at
http://www.kustompcs.co.uk/product.php?subcat=39
 
I have a similar Cooler Master case. I replaced all four fans with
Cooler Master LED fans with the rifle bearings, and used Antec
vibration damping stuff on the front and rear fans. I replaced the
CPU cooler with a Zalman CNPS7000A-AlCu. I use a Matrix Orbital MX212
LCD display/fan controller to run the CPU and case fans. The front
and rear case fans run at about 25% power (PWM) until the interior air
temperature rises above 88F. I leave the top case fan off until the
interior air temperature rises above 89F. This top case fan really is
noisy, so you want only use it as a last resort. The CPU fan runs at
25% power until the CPU temperature reaches 120F. The noise level is
quite acceptable and the fans only kick in when the system is under
load like when gamming.
 
Back
Top