X99 board crossfire question

[Born_2_Kill_83]

When running two GPUS on this board (MSI GAMING 7) :

http://www.overclockers.co.uk/showproduct.php?prodid=MB-281-MS&groupid=701&catid=5&subcat=2875

Do I have to use PCI slots 1 and 3, I would like to use 1 and 5 so I have a larger gap between my GPU's for airflow (top slot and 2nd from bottom effectively).

 

[shankly1985]

That will work fine you will have 16x and 8x

 

[Yaayuh!]

The manual says:

1 GPU = PCI_E1 3.0 x16
2 GPUs = PCI_E1 3.0 x16 + PCI_E3 3.0 x16
3 GPUs = PCI_E1 3.0 x16 + PCI_E3 3.0 x16 + PCI_E5 3.0 x8

So assume that's recommended but if you go 1 and 5 you'll have 3.0 8x maybe.

 

[Born_2_Kill_83]

Running the 5930K so will have enough lanes for 2 GPUs = PCI_E1 3.0 x16 + PCI_E3 3.0 x16, correct?

Slot 5 is a 16X slot

 

[Yaayuh!]

Running the 5930K so will have enough lanes for 2 GPUs = PCI_E1 3.0 x16 + PCI_E3 3.0 x16, correct?

Yep.

 

[Gregster]

Running the 5930K so will have enough lanes for 2 GPUs = PCI_E1 3.0 x16 + PCI_E3 3.0 x16, correct?

Yep.

 

[Born_2_Kill_83]

Excellent thanks for the confirmation

 

[Born_2_Kill_83]

Sorry typo, I ment

2 GPUs = PCI_E1 3.0 x16 + PCI_E5 3.0 x16

Dont want to use slot 5 if its going to be PCI X8

 

[Yaayuh!]

Sorry typo, I ment

2 GPUs = PCI_E1 3.0 x16 + PCI_E5 3.0 x16

Dont want to use slot 5 if its going to be PCI X8

Ah, then most probably will be x8. Most of the time the lowest slots are x8 regardless. However, you'll probably not even notice the difference.

 

[Born_2_Kill_83]

MSI website claims 4 X16 PCI-E slots though

http://www.msi.com/product/mb/X99S-GAMING-7.html#hero-specification

 

[Born_2_Kill_83]

and OcUK's :

4 x PCIe 3.0 x16 slots, support up to 3-way mode
- 1-way mode: x16/ x0/ x0/ x0
- 2-way mode: x16/ x16/ x0/ x0*, 16/ x8/ x0/ x0**
- 3-way mode: x16/ x16/ x0/ x8*, x8/ x8/ x8/ x0**
* For the CPU that supports 40 PCIe lanes
** For the CPU that supports 28 PCIe lanes

 

[Yaayuh!]

MSI website claims 4 X16 PCI-E slots though

http://www.msi.com/product/mb/X99S-GAMING-7.html#hero-specification

and OcUK's :

4 x PCIe 3.0 x16 slots, support up to 3-way mode
- 1-way mode: x16/ x0/ x0/ x0
- 2-way mode: x16/ x16/ x0/ x0*, 16/ x8/ x0/ x0**
- 3-way mode: x16/ x16/ x0/ x8*, x8/ x8/ x8/ x0**
* For the CPU that supports 40 PCIe lanes
** For the CPU that supports 28 PCIe lanes

Interesting. Although, they can't all be x16 at once. But maybe the slot you want will be x16 if you only have 2 cards in?
Never been the case for me on my X79 and X58 boards though but come to think about it, i did have a soundcard in one..

Maybe OCUK can clarify?

 

[stulid]

The bottom two long slots are wired at 8X.

You can tell by pics that the pins inside don't go all the way to the end of the socket.

 

[Born_2_Kill_83]

2 GPUS @ X16 each on a 40 lane CPU you would imagine so, as you said maybe they are interchangeable.

So can OcUK clarify?

 

[Born_2_Kill_83]

The bottom two long slots are wired at 8X.

You can tell by pics that the pins inside don't go all the way to the end of the socket.

Oh

 

[stulid]

http://www.anandtech.com/Gallery/Album/3887#3

That gives the game away.

 

[Silent_Scone]

a few of the boards have obscure layouts

 

[Yaayuh!]

Thanks Stulid.

Next question. How can they be marketed/advertised as 4 x16 slots?

 

[Born_2_Kill_83]

Thanks Stulid.

Next question. How can they be marketed/advertised as 4 x16 slots?

This

 

[Born_2_Kill_83]

This board is going to be a nightmare for my top GPU's temp, its high enough now with a full empty slot between them on the Z77 board, now they'll be no gap to force air between with my extra high pressure fan.