Running a G4/867 24/7???

Question

Hi:
I have an old G4 867 MHz Mac that has been retired but still works well. I would like to use it as a “drone” computer to run SpamSieve. This will require it to run 24/7/365. Thus, several questions:
     1) Any estimates as to how long a computer can run like this before breaking? In the past I’ve only turned it on and off when using it. Obviously, this is impossible predict with accuracy, but any thoughts?
     2) Is there any fire hazard if one runs it 24/7 like this? Is it more likely to overheat?
     3) Once I set it up, is there any reason to keep the keyboard and monitor connected? Once everything is running, I’d like to unplug these items to decrease the physical footprint.
     4) Is there any way to quiet it down? Probably not, but figured I’d ask. Compared to my new iMac and PowerBook, it sounds like a Harrier jump jet!
     5) Any other thoughts or advice?
Thank you!

Answer 1

#1) I have a G4 733Mhz (DA) machine that has been running for about 10 years, 24/7. The only times it has been shut down is when an electrical storm was in the area, or I was going to be out of town for a while (rare). I would estimate its average time off to have been less than 20 hours per year.
Many electrical devices, especially those with motors, suffer more degradation through restaring than through running continuously.
#2) Any electrical device presents a greater possibility of fire hazard if left running unattended. Not because doing so will cause it to overheat; rather, it is because if the device suffers a fault that could cause a fire, there is no one there to notice and take action.
Most Macs since before the G3s will shut themselves down if the interior temperature gets too high. This is done out of concern to protect the CPU from overheating, rather than because of concern for fire safety.
#4) There are ways to quiet it down, but caution should be taken to continue to provide adequate ventilation. This means that replacing the OEM fans with higher capacity, slower fans is usually a much better choice than rigging up some kind of sound-attenuating (and usually airflow restricting) enclosure around the machine.
Curious - if the machine is going to be unattended, why the need to make it more quiet?
One item I alluded to re leaving a computer running 24/7 - electrical storms.
A surge protector and/or UPS will not provide protection against lightning. Such devices can provide some protection with regard to current/voltage surges or spikes, but not against lightning itself.
Lightning follows a connection to ground. Turning off a surge protector or UPS does not break the ground circuit. The only sure way to guard against lightning when it's nearby is to shut down and unplug - this means unplugging not only the power leads to all equipment (or the power lead to any UPS  or surge strips in use), but also unplugging the telephone or cable connection to a modem.