FlexATX PSUs for the MDD G4

[NamelessPFG]

I remembered about several types of PSU form factors smaller than the typical ATX, and FlexATX is the closest to the original MDD PSU, albeit still without the same mounting holes and possibly with even smaller 40mm fans. However, I think those would at least fit where the original would have been, with some clever mounting work.

This would also be a prime opportunity to slip in a modern 80+ certified PSU design, hopefully dumping less waste heat into the MDD case. However, 300-400W PSUs in FlexATX form factor don't come cheap, roughly $60-90 for the good Seasonic and FSP units! Also, you'll have to do something about all the SATA power connectors instead of old-fashioned 4-pin Molex, which would be considerably easier if it's a modular unit (just depin the modular cables with a Molex extractor tool and connect new ones, rewiring the main power cable to MDD spec in the process).

There is one other big concern, and it's that small PSU fans mean LOTS of noise, as the original PSU proved. I haven't seen any FlexATX PSUs that opted for a larger fan on the side, so I'd probably have to whip up a larger fan duct like the one in the stickied MDD silencing effort thread.

Still, as original MDD PSUs continue to die out, this seems like the best method going forward if you don't want to give up your entire optical drive bay to an ATX PSU and don't need ADC power, at least until someone's willing to design a new PSU from the ground up just for the MDD.

Has anyone else put a FlexATX PSU in the MDD before and mounted it without any hassle, perhaps with an ideal PSU model to suggest for the rest of us?

[ELN]

I sure like the sound of this.

[nanopico]

I second this sounding awesome.

$60 -$90 doesn't sound bad at all.  Consider that the average "replacement" (used/refurbished) costs usually around $100 and is questionable in it's dependability, I would have no problem pay $90 for something that I can depend on.

If it's small enough it could possibly be mounted inside the existing MDD PSU enclosure?

[NamelessPFG]

The stock MDD PSU fans are 60mm, while a typical FlexATX PSU has an even smaller 40mm fan or two. That worries me significantly when it comes to noise, but at least clearance won't be an issue.

I've noticed some promising 350W and 500W units from Seasonic with modular cables, which should make custom cables for MDD G4 use an easy job. There's also some 400W FSP units that caught my eye, but they're closer to the $90 end of the price scale and are not modular.

All of those PSUs also tend to pack two Molex LP4 4-pin terminals at most; the rest are SATA, so chances are you're going to need a ton of Molex adapters to use PATA drives and higher-end AGP cards requiring external power.

I took another glance at the stickied MDD water-cooling thread and noted that the poster there instead opted for a SFX PSU, complete with a much larger 92mm fan on the side for intake. Other models might be a bit longer for 120mm fans, just gotta shop around more. I'm tempted to go that route just for the larger, quieter fans, cable splicing be damned.

I presume the dimensions are small enough that it'll still allow the case to close without colliding with any expansion cards, but the AC input's generally not arranged in a place suitable for the MDD G4's AC power cord hole, requiring the user to splice their own AC input cable for a clean look on the outside. The FlexATX route may not require that, but then you get to suffer the fan noise...

Sorry for not having bought any PSUs in the meantime, but I need to make sure ends meet. I'll just make do without any optical drives in the short term while I determine my plan of attack here; besides, I prioritize replacing the crappy Radeon 7000 in this thing with some much better GPUs, one of which will hopefully be here before the end of the week.