VGA card layout

[Spikesoldier]

the last time i can remember a VGA card facing upwards was in a VESA card format.

why do modern manufacturers layout their cards with the core facing down? i can only imagine that it hinders the cooling solution. on probably 90% of towers out there, right above where the VGA card would go are one or two exhaust fans built into the case.

is it just impossible for manufacturer's to do this? i can only think of good things if they switch it around, except with todays heatsinks that gravity might be a problem, but with the heatsink on the other side it would be the same problem, so its really moot?

why dont they switch? you can even make a thicker cooler and really put that CPU heatsink on the card without using PCI slots too!

 

[Shalmanese]

ISA cards faceed upwards, the logical way. PCI cards faced downwards so that the PCI and ISA buses could share the same slot. AGP cards faced the same way as PCI cards so mfgs could make them pin compatible.

 

[cirthix]

it would interfere with the outputs on the motherboard (in the little box with keybaord, network, usb, etc), cpu heatsinks, and chipset heatsinks. its hard to change a standard like this and keep compatability. plus, when they made the unoffical standard, the cards put out so little heat that no fans were needed, just in the power supply

 

[Spikesoldier]

Originally posted by: cirthix
it would interfere with the outputs on the motherboard (in the little box with keybaord, network, usb, etc), cpu heatsinks, and chipset heatsinks. its hard to change a standard like this and keep compatability. plus, when they made the unoffical standard, the cards put out so little heat that no fans were needed, just in the power supply

im aware of that, but if you look at like a 6800U, and flip it around it isnt going to interfere with anything. when you get into double slot cards, maybe.

im looking for a highly technical answer

 

[Sahakiel]

Originally posted by: Spikesoldier

Originally posted by: cirthix
it would interfere with the outputs on the motherboard (in the little box with keybaord, network, usb, etc), cpu heatsinks, and chipset heatsinks. its hard to change a standard like this and keep compatability. plus, when they made the unoffical standard, the cards put out so little heat that no fans were needed, just in the power supply

im aware of that, but if you look at like a 6800U, and flip it around it isnt going to interfere with anything. when you get into double slot cards, maybe.

im looking for a highly technical answer

Standards commitees.

This isn't a highly technical question at all. It gets posted every few months or so and every time it boils down to economics.

 

[Peter]

Card orientation has been standardized, and so have the 3D bounding boxes for the card's physical size.

Besides, the graphics card's orientation has surprisingly little effect on its temperature - because with the way ATX airflow works, there is little difference in airflow. Quite the opposite actually - the exhaust heat from the CPU tends to heat the backside of the graphics card up more.

Finally, making a mirrored AGP card would also require making mirrored AGP graphics chips. The pinouts of the chips being optimized for the connector as it is, you'd have a bowtie knot in your trace routing if you'd attempt to put the chip on the backside of the board.

 

[harrkev]

A lot of it is the reason that when the PCI and even AGP standards were set, vid cards were not the 1000KW monsters that you see now. The AGP slot is a bit older that the first vid card with a fan.

So my guess is that they just didn't consider it.

 

[Maverick2002]

I agree with the economics/standardization bit. If you were to flip the card around, so to speak, the VGA/DVI adapter wouldn't fit the expansion slots on the back of the case. The ATX case spec would have to be redesigned with higher-up expansion slots in order for this to work.

Here's another question. Why on earth is the PSU at the top? Kudos to BTX for changing this idiotic positioning.

 

[Matthias99]

Originally posted by: Maverick2002
Here's another question. Why on earth is the PSU at the top? Kudos to BTX for changing this idiotic positioning.

I would think it's mostly from a thermal design perspective. Most PSUs are used as a system exhaust -- often as the *only* exhaust fan in smaller systems (and remember that they came up with these specs back when even fast CPUs were passively cooled!). Heat rises; it's more effective to have your exhaust at the top of a vertical chassis than at the bottom.

That said, if you're not relying on the PSU to act as your main/only exhaust, there's no good reason to have it there (it just makes the case more top-heavy). And you don't need to wait for BTX; Lian-Li's "V-Series" ATX cases (and possibly others; I don't follow the case scene very closely) put the PSU at the bottom, in its own compartment with a cool air intake.

 

[imported_Kensai]

Perhaps that it's because it helps cool the chip? Well, heat does rise upwards and with the fan sucking the cooler air from the bottom, maybe it would bring better cooling properties to the chip.

 

[Peter]

ATX originally had the PSU inhale cool air and blow it onto the CPU. Didn't work out for too long, because CPU power went through the roof soon after. Graphics card power followed, with little cure because ATX did not design any airflow across the AGP card - be it upside down or not.

BTX has the graphics card in the main airflow - at the end of it, where the air has been warmed by the CPU and the chipset already, but at least it's in some airflow now.