Which slot do I put my graphics card in?

[imnotagamer007]

MSi gaming 7 motherboard and my new 970 is coming in a few days. I read that all 3 slots are x16 speed. So it shouldn't matter which slot I put it in, right?

 

[Winly]

usually the first one, right under the CPU. PCI E 16x

 

[smackers_12]

Usually the top slot is best. Check the motherboard manual

 

[chandan lalit jha]

usually the first PCIe x 16 sloth is best,Cause some motherboard manufacturer company's made first Sloth direct connected to Processor for best graphics performance ..,,,, so i suggest go with first PCIe x 16 Sloth,,,,,,

 

[Wolfshadw]

While your motherboard does have three PCI-Ex16 slots, you only have 16 PCIE lanes between them. The lanes are divided as such (16/0/0, 8/8/0, 8/4/4) If you install a card into the second PCI-Ex16 slot, it will only run @x8 speeds. If you install a card into the third PCIE slot, it will only run @x4 speeds.

You will want to install the graphics card into the top PCI-Ex16 expansion slot.

-Wolf sends

 

[imnotagamer007]

While your motherboard does have three PCI-Ex16 slots, you only have 16 PCIE lanes between them. The lanes are divided as such (16/0/0, 8/8/0, 8/4/4) If you install a card into the second PCI-Ex16 slot, it will only run @x8 speeds. If you install a card into the third PCIE slot, it will only run @x4 speeds.

You will want to install the graphics card into the top PCI-Ex16 expansion slot.

-Wolf sends

I already gave you best answer but can you please explain that a bit more?

 

[Wolfshadw]

Think of each PCI-Ex16 slot as a highway, each with 16 lanes of traffic. However, with the second highway, only eight of the 16 lanes are finished. The other eight are closed. The same goes for the third highway, but in this case, only four lanes are finished. The remaining 12 for highway #3 are closed. Now, regardless of how many highways are in use, you can only have a total of 16 lanes in use.

If only highway one is in use, all 16 lanes are open. (16/0/0)
If only highway two is in use, all eight finished lanes are open. The other eight remain closed (with no way to open them). (0/8/0)
If only highway three is in use, four lanes are open and the other 12 remain closed. (0/0/4)
If highways one and two are in use then eight lanes of highway one are open and eight lanes of highway two are open. Again, you can only have a maximum of 16 lanes in use at any given time. (8/8/0)
If highways two and three are in use, then eight lanes of highway two and four lanes of highway three are in use. All other lanes are closed. (0/8/4)
If all highways are in use, then only eight lanes of highway one are in use, and only four lanes of each highway two and highway three are in use. All other lanes are closed. (8/4/4)

Hope this helps.

-Wolf sends

 

[imnotagamer007]

Think of each PCI-Ex16 slot as a highway, each with 16 lanes of traffic. However, with the second highway, only eight of the 16 lanes are finished. The other eight are closed. The same goes for the third highway, but in this case, only four lanes are finished. The remaining 12 for highway #3 are closed. Now, regardless of how many highways are in use, you can only have a total of 16 lanes in use.

If only highway one is in use, all 16 lanes are open. (16/0/0)
If only highway two is in use, all eight finished lanes are open. The other eight remain closed (with no way to open them). (0/8/0)
If only highway three is in use, four lanes are open and the other 12 remain closed. (0/0/4)
If highways one and two are in use then eight lanes of highway one are open and eight lanes of highway two are open. Again, you can only have a maximum of 16 lanes in use at any given time. (8/8/0)
If highways two and three are in use, then eight lanes of highway two and four lanes of highway three are in use. All other lanes are closed. (0/8/4)
If all highways are in use, then only eight lanes of highway one are in use, and only four lanes of each highway two and highway three are in use. All other lanes are closed. (8/4/4)

Hope this helps.

-Wolf sends

But all 3 of my slots are x16 slots so shouldn't all 16 lanes be open for each slot?

 

[Wolfshadw]

No. They all conform to the PCI-Ex16 physical standard (they all will accept a PCI-Ex16 expansion card), but the last two are hard wired for fewer lanes; limited by the total number of PCIE lanes available (16 total lanes for all three PCI-Ex16 slots).

-Wolf sends

 

[rabaker07]

dupe

 

[rabaker07]

No. They all conform to the PCI-Ex16 physical standard (they all will accept a PCI-Ex16 expansion card), but the last two are hard wired for fewer lanes; limited by the total number of PCIE lanes available (16 total lanes for all three PCI-Ex16 slots).

-Wolf sends

Are you absolutely sure about this? I put my card into the 2nd slot because it was too crowded next to my CPU cooler, etc. On first boot it had to search for the card, but it found it and after a cycle or two, reconfigured the BIOS to now use the 2nd slot as primary. Do you have any documentation on this deficit and limitation of only 8 lanes by using 2nd slot discretely?

Asus Z170-AR Mobo
i5 6600k @ 4.6
Vengeance DDR4 3000hz
GTX 980 Ti

 

[Wolfshadw]

No, I don't have any documentation other than what is implied by the user manual. I'd probably download and run HWInfo to see if the limitation is there.

-Wolf sends

 

[rabaker07]

No, I don't have any documentation other than what is implied by the user manual. I'd probably download and run HWInfo to see if the limitation is there.

-Wolf sends

Hi Wolfshadow, I didn't see this response way back when. I posted my HWInfo below and it looks like I'm using all 16 lanes in slot #2, but can you confirm?

 

[Wolfshadw]

It states:

PCIe v3.0 x16 (8.0 GT/s) @ x16 (8.0 GT/s)

So, I'd say you're good to go.

-Wolf sends

 

[rabaker07]

It states:

PCIe v3.0 x16 (8.0 GT/s) @ x16 (8.0 GT/s)

So, I'd say you're good to go.

-Wolf sends

Sweet, thanks for confirming. That's what I thought but it's always good to get a moderators nod...