Sun Fire v440 has been placed in the same room, where i'm working. It seems that it makes much more noise, than reactive plane does.
I've already updated ALOM Firmware and even OpenBoot PROM, expecting that there were some new features in these updates. But I haven't found anything interesting…
Is there some other way to reduce the noise level except power off server?
Servers are noisy, that's what they do.
You have three options;
1 is stupid, reducing the fan speed is NEVER a suitable option, 2, 3 and 4 will cost. Up to you, there is no magical software fix that will make servers quieter.