New G5 casemod: best postition for motherboard?

[I-Heine-I]

I am currently working on a G5 ATX conversion but I have one thing which I yet have to decide. I really want to keep the stock look on the back of my G5. But the problem, of course, is the fact that fitting the motherboard directly to the back of the case will force you to cut out space for the motherboard I/O panel. Thinking of this, I came up with the idea of placing the motherboard slightly to the front of the case (so the PCI cards will not be mounted directly to the rear slots). When a GPU is installed, I could simply use a DVI bracket with a DVI extension cable attached to extend the video output to the rear slots.

 

Common version

 

Alternative

 

A DVI bracket:

 

This might work, although I have two major concerns:

- I am planning to use a high power GPU (ATI HD5850) in this build. The GPU blows out it's heat at the back of the card, through its mounting bracket. When placing the back of the GPU in the case, the GPU may not be able to blow all it's heat out of the case. This may be solvable by making a air duct which extends to the back of the case to guide the heat out of it. I would also replace the stock expansion slot brackets with ones with ventilation holes.

- Is it okay to fit a pretty heavy GPU just to a PCIe-slot, instead of also attaching it with a screw to the case? I'm slightly worried about the amount of weight which will be put on the motherboard because the GPU is not attached to the case itself.

 

I am planning on using a Gigabyte M-ATX motherboard with this build.

 

I would really appreciate any feedback, thanks in advance!