Originally posted by: her34
3) with gpu's facing right side up, you could have fans that are perpindicular to the card instead of parallel, again leading to better and quieter cooling
They still wouldn't be likely to do that, it would just be too likely to bump into something like the main cooler shroud, and what about an SLI board, where you've still got another card sitting on one side or the other for it to hit, and slots in between that are rendered unusable. BTX doesn't take SLI into account at all of course, no cooling provided to other slots.
It just becomes a mire of various systems that are slightly incompatible with each other, and more people complaining to tech support. Besides, dual-slot coolers already should provide pretty close to the same performance, unless you want to make the heatsinks themselves take up even more space.
As for PCI slots facing right side up, they could have just made the PCIe spec point them in the right direction, if it mattered. If a device is supposed to take up only a certain amount of space, it shouldn't matter which way it's facing in terms of combinations of PCI and PCIe slots. I don't think the chips and components on a card will get significantly better cooling simply from facing upward, compared to the cooling action of airflow, and if you have more than two cards, you just change the direction that the heat is radiating from one into the other.
Of course if you look at manuals, the tech makers all seem to think we have actual desktop machines laying flat on the desk. The cards are vertical there, so the PCI orientation doesn't matter.