Video Card Design

[justChel]

hey guys, i've read Anandtech for many years now almost weekly, but this is my very first post, and i don't know the rules or how to navigate "threads" very well. Anyways, this is an awesome sight.

My question is why do video card manufacturers design the cards with the core/memory and the rest of the key components facing down when installed in a tower? so as all the heat generating chips are on the underside of the card and possibly could also be sandwiched close to other PCI cards. No wonder some beefy video card cooling systems require "dual slot" solutions. why don't they put that stuff so that it is on the top of the card when installed in a tower and take advantage of the extra room it would have to breath in a more open part of the case since the video card is the first card installed in the expansion slots. does this make sence? anyone get what i'm saying? there can't be much cooling going on when my video card's fan is blowing down right into my other PCI cards, even with the 2 free PCI slots underneath it. anyone have ideas, or answers? thanks a lot for checking out my post, and have an awesome weekend.....

 

[ribbon13]

because if there were on the top they'd still be sandwiched? Maybe's is so the heat flows to the edge of the card and upwards to the airflow of the case instead of rising and heating up the card above it or in the video cards case the CPU? The PCB helps diffuse the heat. Maybe it's not just video cards, but most expansion cards, and actually was part of the MLB/ISA/EISA/VESA/MCA/PCI/PCI-X/PCIe specifications?

 

[Bobthelost]

Because the layout is pretty much the only one for ATX standards, some cards have been made to exhaust the air upwards, but there are compatability issues with how you'd mount them in cases. The incentive to make them just isn't great enough.

 

[corkyg]

Yep - it has been pretty much standard ever since the ATX mobo was adopted. In a tower, that puts all the components on the "under" side of the board. It does provide for better cooling in that they are then away from a main heat sources - the power supply and the CPU.

It is somewhat of a standard - otherwise adjacent boards could interfere with one another if chips, resistors, capacitors, etc.,were not all on the same side.

If the case is not a tower, then the back plane is on the left and the chips, etc., are all on the front of the boards.

 

[Pariah]

Having the components facing down actually improves cooling because it minimizes the amount of dust and junk that will settle on the card. Dust settling on the top of the card with nothing there doesn't cause any problems, if the components were flipped so they were on the top, all the dust would settle on the chips and clog up the fans much worse than they do now.

Facing the components upward would also cause clearance issues with the chipset/CPU/DIMM slots for many M-ATX boards. So the logical design choice was to have the cards face downwards.

 

[jdkick]

I pondered this at one point. We all know heat rises... with the current design of video cards, the PCB is, in theory, preventing heat from rising. I don't know what kind of gains we'd see if the orientation of the GPU/memory was reversed, but i'd be curious.

 

[imported_Kiwi]

Once upon a time, PC's almost all were housed in horizontal boxes. The first standard was IBM's, and became known as ISA for "Industry Standard A(something like Architecture). Those were offset on the "right" side of the card cage slot, with the main components on that side. When PCI came along, and the initial MB designs had both ISA and PCI slots, one of the brainstorms they thought of was having a "shared" card cage position.

The last PCI slot and the first ISA slot both were intended to use the same opening from the backplane. So only one or the other could be there, and so the PCI card is offset to the left, to allow this sharing of that card cage position. Only servers were in retailed tower boxes, plus a few enthusiasts' boxes among the early PC home builders.

With the card offset in that direction, the components ended up on the left side of the card.

Just a little history lesson for tonight (my own first home built was a 286-12 in a Mini-Tower).

 

[imported_Nacelle]

I have an old case that has the mobo upside-down in it. The cards are all at the top w/the fan facing up.

 

[bamacre]

My 7800 GTX faces upwards in my Dell 9100 (BTX?).