MDD - Newbie in need of advice

Posted by: cmcenearney

MDD - Newbie in need of advice - 09/20/06 02:59 PM

Background:    I did some research on this computer but somehow failed to learn of it's infamous handle, "the windtunnel". I bought it used and when I was checking it out there was a lot of background so I didn't notice the problem.

The Problem:  The noise. I like to record and do various audio things, so it's really a problem, although, considering that you can hear this thing from the bedroom down the hall with the doors closed, it's a problem no matter what.

Solutions:    So, after looking around on this site and I have been very inspired to see that people overcome this problem in numerous ways:

1) swap out the psu fans
2) swap out all the fans
3) do a complete ATX case conversion ala the "Killer Bee" and "Silent ATX G4" mods which are featured on this site
4) keep the case and do all kinds of stuff ala the "unreal G4"


1) Can an atx psu be adapted to work with the MDD mobo? According to this the MDD has 24 pin pinout: 
versus the standard 20 pin atx pin-out:

I am a total novice, but they look significantly different to me. Also, does the 25v or 28v pin do anything besides power an apple monitor? I don't plan on using an apple brand monitor.

2) If I keep the stock case, will adding more hard drives and pci cards increase the noise problem?
I have heard that this is the case, due to poor airflow.

3) Does anyone want to buy a dual 1.25 MDD? It's in great shape.... smile
Posted by: maestro

Re: MDD - Newbie in need of advice - 09/20/06 03:38 PM

First of all, you own one of the fastest PowerMacs of all time.  No, its not Mac Pro speed, but it did whip several models of G5s.  I think the big thing is whether you want to mod your case or use a new one.  I would go with a PC case.  Just that move will help a lot.  Its a tough mod for the inexperienced though.  The fans can and should be replaced.  I suggest Panalfo Ls.  Yes, there are quieter fans, but they dont move that much air.  You can set up a fan controller to run all of the fans.  The MB wont care.  I suggest the copper heatsink too.  It will take some money to get this Mac where you want it, but I have owned dual G5s too and still come back to the MDD as my main workstation.  The G5s made annoying beeping sounds, though the fans are much quieter.

One more thing...this models has a ton of expansion which keeps the G5s from coming back to my work area.  Okay, two more things, you could sell it and buy a Mac Pro or buy a MacBook pro.
Posted by: cmcenearney

Re: MDD - Newbie in need of advice - 09/20/06 05:20 PM

Thanks for the reply.
Yeah, I know it's a great machine in many ways. I have a lot of work in OS9, so I like the fact that it's the fastest OS9 bootable mac ever made. I mean, in theory it's all stuff that can be moved to OSX, but still.  And expansion. My last computer was a 667 powerbook, and I got tired of always hooking up firewire drives, plus I would like to be able to use some pci devices.

Anyway, I noticed that on your Killer Bee mod you kept the stock psu (with replacement fans). Why not replace it? There are lots of silent psu's out there. Is it too much of a pain?

This conversion uses a pc psu, but he doesn't explain how he wired it, only that it is "custom".

As for a MacPro, I don't have that kind of dough!
Posted by: cmcenearney

Re: MDD - Newbie in need of advice - 09/20/06 05:35 PM

Oops, he does mention this:

I made an ATX extender cable and modified the 2 wires required using a previous mod guide, and secured the new cable to the logic board tray.  This allowed me to use an off the shelf, unmodified ATX power supply that should make replacement easier in the future. 

Still, going by what I've found so far, it looks like you'd have to modify more than 2 wires, as the MDD psu is 24 pin.
Posted by: Waragainstsleep

Re: MDD - Newbie in need of advice - 09/20/06 07:15 PM

The extra two provide a 30V feed to power an ADC monitor. If you don't use one, you don't need them.
Posted by: cmcenearney

Re: MDD - Newbie in need of advice - 09/22/06 05:08 AM

After some more thought I'm considering just putting the G4 in a closet and getting a 10 meter DVI-D cable. I see them for $50. I'm wondering if there's any reason not  to do that...
Posted by: godicm

Re: MDD - Newbie in need of advice - 10/24/06 09:19 PM


you are not the first hiding your mdd in the next room.

abt the psu: i once tried setting a quicksilver to work with a atx powersupply (w/o 28V for ADC).
didnt work. the LoBo seemed to require the 28V for powermanagement. dunno if the MDD would work.
just try.
pinouts can be found here