fans going into "hyper" mode ?
 

I was wondering what it is that causes the mac to freeze up and then cause the fans to go into hyper mode?.If it has happend to you you will know what i mean, The only thing that sorts it is holding in the off button and leaving it a min. I was wondering if it is just needing more memory....it has 2gig in at the moment but i do have a feature length film in it which could be drawing too much memory.

Any thoughts

Andy.

The fans respond to the intensity of processor usage. If the system should go into an infinite loop somehow, this will cause the fans to go to max. It's not uncommon for the system to become unresponsive and max out the fans if it has a lot of stuff to chew on.

-gb-

Thanks Greg, nothin to worry about then :)

Andy.

The fans go into hyper mode when the Mac freezes because the Mac can no longer regulate its internal temperature automatically; the fans kick in to full effect just to be safe.

If the total freeze is happening a lot, I would investigate. I had a G5 that started doing it with increasing frequency, it ended up getting replaced because after a while it wouldn't stay on for more than 5 minutes.

The replacement G5 Quad hasn't had a single hiccup since I got it a year ago.

Do you see anything on the screen? Or is the screen off (like from a screensaver)? If the machine appears to be unresponsive and the fans are running full-blast, then you've probably suffered what's called a "kernel panic", or a complete system crash. OS X is pretty robust, and almost impossible for an application to crash (FCP for example). BUT, if you have any of the following problems, they can lead to a kernel panic. I'd be very wary...I had a G5 Quad that was prone to these, and ended up needing a new motherboard.

1) bad or borderline RAM (can fail under high thermal load)
2) bad or borderline motherboard
3) poorly-written hardware drivers (do you have any low-cost Firewire drives?)
4) bad or borderline hard drive where OS X is installed