I currently have a Panaflo 80 mm L1A fan mounted on a Thermaltake SLK-800A (AMD Athlon XP 2500+ "barton" @ 3200+).

Speedfan reports that it idles at 80% (~9.6V) and ramps up to 100% (12V) at 100% CPU load.

How would an 80 mm Panaflo H-1BX (FBA-08A 12H-1BX; rpm monitoring) at 5V - 7V compare noise-wise to the L1A, both in terms of absolute level and the quality of the noise (any distracting clicking, etc?)?

Uh... it'd be louder. A LOT LOUDER. If you need more cooling, go with a M1A-BX, or simply tell us your case setup, and perhaps we can help you figure out how to improve your setup such that the fan wont ramp up as much.

Right now, the Panaflo L1A provides quite acceptable cooling at idle and ~ load.

I would just like a little more "overhead" so if I do some gaming, CPU temps don't bump up much (I have Speedfan set at 53 C, and with light gaming the temps bump up to 56 to 58 C and the Panaflo L1A ramping from 80% to 100%). Non-gaming loads only seem to bump up temps to 54 or 55 C, again with the Panaflo at 100% speed.


Why isn't a significantly undervolted H-1BX approximately as quiet as an L1A, if both are pushing approximately the same cfm (and similar rpms?)?

Shouldn't the M-1BX have similar spl as the H-1BX, if both are both are pushing similar, but non-maximal cfm and presumably rpm?

Also, do all Panaflo 80 mm M-1A fans have rpm sensing or do I specifically have to look for a BX model?

Look for the M1A-BX. That has fan monitoring. The medium speed provides improved airflow compared to the L1A, while not going to extreme speeds as the H series. The H series is LOUD, no matter what voltage/speed you run it at.

I'd bet the voltages are more or less different than the calculated values. Most, if not all motherboards use PWM to control the speed, and depending on the design, with low-current fans, the "voltage" range is not what one would calculate on paper.

You could test the fan with Zalman Fan Mate (or similar fancontroller), and measure the voltages/temperatures. Your load temps seem OK if your room temp is more than 22°C, and/or the temp doesn't climb much higher than the present.

Cheers,

Jan

I finally finished my setup. I got a Panaflo FBK12G12LH undervolted with one of those generic fan controllers. I am really happy with the results. At around 7 v, the damn fan goes nearly silent. At 5 volts, its inaudible!