Is the iMac supposed to be completely silent ?

[vslo]

Or its normal to hear a low noise from the fan ? Both my new 21,5 iMacs are hearable when its very quiet around... Both have their fans running in 2100RPM, using fancontrol.
So , when its very quiet around, can you guys hear something ?

[spinnerlys]

As the idle fan speed is 1200RPM on both CPU and HDD fans and 1000RPM on the ODD fan, 2000RPM is hearable.
Fan Control is not really needed with the Mac, unless you put the CPU to constant high usage (60/120/% upwards), the iMac is able to handle temps of more than 100° C with the CPU.

[alust2013]

When it's very quiet, and you're listening, yes you will be able to hear them. Hard drives and fans simply make noise, and there really isn't a way around that. I'm not particularly familiar with the fan speeds of an iMac, but 2100 RPM sounds a little high, unless you are doing heavy processor work and need them that high. Someone correct me if I am wrong though.

[aliensporebomb]

It isn't supposed to be completely noiseless. It contains mechanical devices. They can make noise and will.

[TMRaven]

There's really no reason to be running your fans at 2100rpm through an application.

There's also really no reason to complain about the fan noise when you're unnecessarily reving up the fans on your own accord!

[Spike88]

I use FanControl program on my iMac 21.5" as well. I set the fans to minimum 1600 RPM and "on average", I see them running at 1800 RPMs. If wondering, I use iStat Nano to randomly check both fan speeds and internal temps. Yes. I can hear fan speeds of my iMac. And that's ok with me. At 2100 RPMs, I bet I could easily hear them. Not too sure why fan RPMs at set above 1800 RPMs (as minimum).

Perhaps one can set to 1600 RPMs (as minimum) and do another sound check. Works for me....

[Fishrrman]

"Or its normal to hear a low noise from the fan ? Both my new 21,5 iMacs are hearable when its very quiet around... Both have their fans running in 2100RPM, using fancontrol.
So , when its very quiet around, can you guys hear something ?"

Of course it's "normal".

If a device has moving parts, it's going to generate some sound.

Some computers generate more sound than others.

The iMac is "on the quiet side", but the only time it's going to be "silent" is when it's sleeping, with the hard drive spun down and the fans stopped.

I snicker when I see complaints here about "noisy iMacs". I have a g4/MDD "wind tunnel" Mac. You ought to hear that!