quick motherboard layouts pci layout rant

[mhouck]

I've been looking at the 1366, 1156 and 890fx boards recently and have noticed that tons of boards have the pci-e (1,4, ect.) almost exclusively positioned one slot below their first or second PCI Express 2.0 x16 slots. I can't understand why the manufacturers are doing this.

All highend and a great majority of midrange GPU's for the last couple of generations have been dual slot. With the most extreme GPU's going to 3 slots I can't understand the mindset in their layouts.

I know there are boards that have pci slots positioned away from the PCI Express x16 slots but why would any enthusiast board choose such an increasingly counterintuitive configuration?

 

[AstroGuardian]

You can put a PCI-e card on the x16 slot and it will run. They are just giving you an extra "x" on that slot. It might be just that... However i can't explain it thoroughly.. srry

 

[Sahakiel]

Because anybody who absolutely needs to use a PCI slot isn't using dual-slot graphics cards.

I'm more annoyed there are even PCI slots on the board.

 

[mhouck]

Because anybody who absolutely needs to use a PCI slot isn't using dual-slot graphics cards.

I'm more annoyed there are even PCI slots on the board.

I'm using 2 dual slot cards and need the pci slot for my wireless card. i know i could get a usb adapter to replace it, but I'm ridiculous and will buy a $200 plus board and not want to spend an extra $40 or so dollars on something I don't necessarily need.

 

[Modelworks]

Another reason is because the more slots the more flexible the board appears to buyers.

 

[deimos3428]

This is particularly annoying if it is the only slot of it's type on the board. Nobody wants to preclude their use of crossfire by using an x16 slot for an x1 or x4 card (eg. tv tuner), and on a non-crossfire board there might be no remaining option to use the card at all.

I think part of the reason might be that crossfire connectors are too short to place the PCI-E 2.0 x16 slots farther apart. We are reaching the limitations of a seven-slot design, and triple-slot coolers exacerbate the problem.

It's equally annoying that dual-slot GPUs are "upside down"; ideally the HSF should be on the top of the card because heat rises. If you're going to block two slots anyway...put the PCB in the bottom slot and blow the air up!

 

[Suspicious-Teach8788]

I'd like to see a better PCI-e x16 layout for the first 2.

First of all. The number of users going single card > dual card > triple card. There's so much emphasis about TRI-SLI now that even dual SLI is compromised. With some coolers extending 2 slots BELOW now, they shouldn't just make 1 slot between the first 2 PCI-e x16 slots.

Either allow people to use the first and last PCI-E slots for dual SLI or put the middle one further away. Anyone who's running tri-SLI knows they have to make compromises. Possibly no other expansion cards because dual slot coolers x 3 = 6 slots taken up.

However for those running 1 or 2 cards, MORE possibilities exist. They should keep in mind to maximize those possibilities with 1 or 2 cards.

Having PCI slot directly below your PCI-E x16 is retarded as anyone with a single card will already be screwed due to cooler size.

Current:

1) PCI-e x16 (Single card)
2) Crap
3) PCI-e x16 (Dual SLI)
4) Crap
5) PCI-e x16 (Tri-SLI)
6) Crap

They should shoot for flipping 3 and 6 around. Yes we'll need longer x-Fire/SLI ribbons but that's a few cents at most.

Also the large heatsinks of the north bridge cause a lot of problems. Many boards only have room for 6 slots. Some like Gigabyte still offer 7.

 

[deimos3428]

I'd personally like to see something like this:

1. PCI-E x16
2. PCI-E x1 (blocked by dual-slot GPU#1)
3. PCI (legacy, only blocked by a triple slot cooler)
4. PCI-E x16
5. PCI (legacy, blocked by dual-slot GPU #2)
6. PCI-E x1 (only blocked by a triple slot cooler)
7. PCI-E x4

That would give most people access to most slot types, I think, and should be doable on a 790GX with 22 PCI-E lanes. There are two legacy PCI slots and two PCI-E x1 or x4 slots, one of each type is likely to be blocked. In the case of two triple-slot cards, you're still going to lose legacy PCI but will still have an available PCI-E x1/x4. That last one could even be a PCI-E x16 if the chipset supports enough lanes, and there aren't any tall components below it -- so you can overhang a third dual-slot card.