View Full Version : G4 with ADC - max power limit?

Mar 12, 2009, 09:13 AM
Hi there

Just upgraded my G4 AGP (the Gigabit ethernet version) to act as my home server. It now has 2x120GB IDE drives, one of which is the boot drive, and 2x1TB WD Black SATA drives running in Mirrored RAID - these are running off a Sonnet PCI SATA card.

Now, all seems fine, but I noticed when I had the case open that the PSU claims to have a maximum capacity of 195W, and from memory the 15" Apple Studio Display takes about 40W to run off the ADC connector. So my concern is whether going to 4 hard drives at the same time as running an ADC monitor will overload the PSU.

For now, therefore, I'm running the machine into my regular monitor through the D-SUB output and with the keyboard and mouse into the normal USB ports in an attempt to minimise the power draw, but I'm curious to know whether anyone's got any experience in this area - have you ever blown one of these PSUs by overloading? Am I worrying about nothing?

My main concern is that I seem to remember these PSUs aren't normal ATX jobs, so replacing it with a more powerful one will require a cable adapter or some soldering, neither of which I'm really up for.

Incidentally - what a truly great machine to work on, having painfully upgraded many PCs over the years. Pop the side down, slap in more RAM, slide the drive "sleds" out and add 4 hard drives. It's an absolute joy of a machine.

Earl Urly
Mar 12, 2009, 10:45 AM
If you overload it, you'll just smell an acrid burning odor and your machine will shut down shortly thereafter, or your machine will simply refuse to POST, the light will go on but no fan or hd boot.

If you're interested in replacing the Apple PSU with something more robust, check this place out:


The site owner sells adapter cables and also documents how to make your own adapters, and also recommends certain models. The best models resemble the Apple PSU in terms of port/socket/cable placement.

Mar 15, 2009, 08:17 PM
I've been running a g4 mdd with a sata card, four hard drives, wifi card, and a 15" ACD for over 2 years solid running. You'll be fine. Powermacs are tanks

Mar 15, 2009, 09:19 PM
My dad has a MDD Dual 1ghz with 5 Hard drives and a 24" ADC and he has had no power problems.
Don't know if that helps but you can get a new power supply like Earl was saying if it makes you feel better. But I don't think you should worry.

Mar 16, 2009, 08:50 AM
Ah, that's good to know - thanks for that. If I was focusing on space I'd just leave it on a KVM switch into my normal monitor, but the ACD is a beautiful bit of kit so it seems a shame to hide it away!