TLDR it breaths probably better than a lot of other rigs.
Ya I was concerned about that too. So I re pasted the voodoo 3 with some Noctua NT-H1.
Plugged in the Top Tech III Temperature Sensor that comes on this board and inserted into the voodoo heatsink. That way I could read the temp of the Voodoo.
I built a fan bracket out of some old drive bay adapters and screwed it to the back of the case to blow air on the voodoo and m3d. Plus theres a front 80mm fan that is also pulling air from outside and blowing into that direction.
I'm sure it's not that accurate btw. But I havn't seen the voodoos temps over 40c.
I would of moved the A3d over to slot 2 except for whatever reason the AGP card shares the IRQ of the 2nd slot. While nothing shares an IRQ with the 1st slot so I'm able to make the build work this way.
Anyways it works like this.