CPU from MDD in a Gigabit Ethernet?

[protocol7]

So I never did get my dead PSU MDD up and running. It's just been sitting there doing nothing with (what I believe to be) a dual-1.24 G4 CPU.

I just got to thinking... would the CPU work in one of my Gigabit Ethernets? I have dual-450 and dual-500 models. The bus speed is a lot lower (100Mhz vs 167Mhz) so would that bottleneck the CPU to the point where it's not worth the upgrade? And would the stock PSU and fans be enough?

I don't really need the power but if the pros outweigh the cons then I might as well put that sucker to use until I get a replacement PSU.

[BGoins12]

It won't work. MDD CPUs are MDD specific.

[protocol7]

That's that idea shot then. I assumed they were all more or less swappable.

[ClassicHasClass]

The MDD and original Xserve share the same CPU model, but otherwise that's about it.

[theos911]

http://www.jcsenterprises.com/Japamacs_ ... ssors.html

That is one of the best resources I've seen on these things.

While switching from one model up or down is sometimes possible, going from the top 167 to the bottom is going to be no go.

[Bunsen]

Excellent find theos911. As this is a question that comes up fairly regularly, I've added it to a sticky thread at the head of this forum.

[protocol7]

Agreed! That's one to keep handy.

[Bolle]

What are you doing with that CPU now? Just curious as I have been looking for a 1.25 for my MDD. eBay prices of those are a joke compared to what full 1.25 units cost and I do not want to end up with another not working MDD. Just in case you want to get rid of yours.

[protocol7]

Hoarding it for now. Like I do with all my Mac stuff. I hope to get it going at some stage. Just looking for the right PSU to come along.

If I end up parting with it I'll let you know.

[waynestewart]

You could also adapt an ATX power supply. Google will find you several sets of instructions. Might be a better choice as MDD power supplies are their weakest point

Hoarding it for now. Like I do with all my Mac stuff. I hope to get it going at some stage. Just looking for the right PSU to come along.

If I end up parting with it I'll let you know.

[protocol7]

I ATX-ed my first Gigabit Ethernet. But the PSU in the MDD is different. It's a slim style (like those found in rack units). It's possible to hang a ATX PSU in a MDD but it looks pretty bad. I'd rather hold out for a replacement PSU. I wondered about taking the guts of a working rack unit PSU and transplanting them into the MDD's PSU casing. But never found a suitable donor PSU.

[theos911]

My QS '02 went through two PSU and then I gave up. Is there a common failing point in these, or is it a general poor design?

[BGoins12]

The MDD's power supply is a bad design, IMO. I just don't like the fact that it sucks in hot air from the inside of the computer and exhausts it out the back. They should have installed a shield on the supply that sucked the air in from the outside. The air that comes out of my MDD's supply is insanely hot. I have the ACBel 400w supply (The "loud" one)

I'm still thinking about drilling some holes in my case, and fabbing a shield so that it sucks it in from the outside. The side of my case might have holes in it, but they would be effective and useful.

[theos911]

Is it possible to simply turn the PSU fan around? I've done this with some CPU fans in the past to surprisingly stunning results.

[jruschme]

The MDD's power supply is a bad design, IMO. I just don't like the fact that it sucks in hot air from the inside of the computer and exhausts it out the back. They should have installed a shield on the supply that sucked the air in from the outside. The air that comes out of my MDD's supply is insanely hot.

Funny, I always saw sucking hot air into the PS and venting it out the back as the norm. What surprises me, though is that the fans seem on the wrong end (i.e., you don't so much suck hot air out the P/S as push it through the P/S).

I was also greatly suprised to see that the portholes in the front are much less functional that I would have expected. Also lots of places where vent holes in the sheet metal don't match vent holes in the plastics.

[waynestewart]

Some of the micro ATX power supply are slim enough to fit a MDD