27'' iMac --- How many hours can it run ?

[Bob800]

I usually have my 24" iMac "on" for weeks, if not months without problems. I just put it to sleep when I sleep. That means 15 hours on every single day. After a few weeks it might get a bit slower, but reboot always helps there.

[nyne]

I was told that the bigger screens heat up so need rest, or they breakdown after some time from over use.
Was this ever an issue with the 30" Apple display as well ?

[santibanks]

i7 Imac Heat Issues - Mac Forums

Apple - Support - Discussions - 27" Quad Core i5 iMac having heat/fan ...

indeed, there are some problems reported. Try to contact apple in case you really get into problems.

[drbam]

Had mine for about 3 weeks but it is my personal/home business machine and never gets pushed to do anything CPU intensive. I have to put my ear next to the screen to hear the fan - occasionally I can hear the very slight sound of the HDD doing its thing if the room is dead quiet and I'm close to the screen. So far, so good.