Which PCIe slot should my GPU be in?

[Turbo Soggy]

I got a custom build PC from a place in my town and the guy who built it put the GPU in the second PCIe slot. It's a ROG STRIX B450-F motherboard: https://www.asus.com/us/Motherboards/ROG-STRIX-B450-F-GAMING/
Is the second slot x8 only, or does it also support x16? Should I go back and have him change the slot to the first one? I'm not super technically inclined and can't decipher the info on the PCIe slots.

[Supafly]

Without even looking at the motherboard specs I can say the GPU will need to be in the PCIe slot closest to the CPU. Or highest slot if you look at it while its vertical in a tower case.

[Turbo Soggy]

Originally posted by Suicidal Monkey:

Without even looking at the motherboard specs I can say the GPU will need to be in the PCIe slot closest to the CPU. Or highest slot if you look at it while its vertical in a tower case.

Looking at the specs it seems to me like maybe the both support x16, but I can't tell.

[HypersleepyNaputunia]

closest to cpu has less distance for signals to pass through,

[Jaunitta 🌸]

Originally posted by MM24:

I got a custom build PC from a place in my town and the guy who built it put the GPU in the second PCIe slot. It's a ROG STRIX B450-F motherboard: https://www.asus.com/us/Motherboards/ROG-STRIX-B450-F-GAMING/
Is the second slot x8 only, or does it also support x16? Should I go back and have him change the slot to the first one? I'm not super technically inclined and can't decipher the info on the PCIe slots.

He may have put it in the 2nd slot for better airflow. Less heat between the cpu and the gpu then.
It will be fine just leave it there
according to your own link it could sit in either the top slot or the 2nd slot both the same.
Multi-GPU CFX support
2 x PCIe 3.0 x 16 (supports x 16, x8/x4)
1 x PCIe 2.0 x 16 (at x4 mode)
3 x PCIe 2.0 x 1

[Supafly]

Ok at quick glance yes it has 2 that support x16

Multi-GPU CFX support

2 x PCIe 3.0 x 16(supports x 16, x8/x4)
1 x PCIe 2.0 x 16(at x4 mode)
3 x PCIe 2.0 x 1


Without checking the manual to identify which are which I'd install the card in the top most slot as I mentiined earlier. But it'll be fine in the other x16 slot. No need to return it if it needs to be moved. Just power PC off, remove the side panel. Touch the case to ground yourself and remove the GPU and plug it in the other slot. Really isnt a difficult task

[Jaunitta 🌸]

Steam community screenshot 

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By: Jaunitta 🌸

2 pci slots

[Clint E]

Originally posted by PuertoRicanStripeHeadedTanager:

Try putting it in and if it doesn't fit perfectly it doesn't go there.

Lmao 😂

[Overseer]

Unless you have very specific reasons to have it in PCIE_X16_2 i would recommend to move it to PCIE_X16_1. You don't need x16 for anything below 2080 or even 2080 Ti, but x4 can hold even mid-range cards back.
I think PCIE_X16_2 is x4 only and PCIE_X16_1 will run at x8 if two cards are installed.
And all of that only counts for Ryzen CPUs without Vega graphics. As the integrated graphics processors come with less lanes.

[Turbo Soggy]

Originally posted by Overseer:

Unless you have very specific reasons to have it in PCIE_X16_2 i would recommend to move it to PCIE_X16_1. You don't need x16 for anything below 2080 or even 2080 Ti, but x4 can hold even mid-range cards back.
I think PCIE_X16_2 is x4 only and PCIE_X16_1 will run at x8 if two cards are installed.
And all of that only counts for Ryzen CPUs without Vega graphics. As the integrated graphics processors come with less lanes.

I'm not confident enough in myself to change it myself, so I'll just leave it as is.

[TehSpoopyKitteh]

Originally posted by MM24:

Originally posted by Overseer:

Unless you have very specific reasons to have it in PCIE_X16_2 i would recommend to move it to PCIE_X16_1. You don't need x16 for anything below 2080 or even 2080 Ti, but x4 can hold even mid-range cards back.
I think PCIE_X16_2 is x4 only and PCIE_X16_1 will run at x8 if two cards are installed.
And all of that only counts for Ryzen CPUs without Vega graphics. As the integrated graphics processors come with less lanes.

I'm not confident enough in myself to change it myself, so I'll just leave it as is.

As long as it is the longest PCIe slot availible, you should be just fine. I have multiple 16x slots, but I chose which one to install my video card based on potential airflow. In that perspective, the front fan has zero obstruction as most of the cabling in that section is routed below it.

[Ad Hominem]

Just by looking at the picture of the board on the linked website, the second slot says PCI 16_2, which would say to me that it's a PCIe 3 x16 lane slot, so you're golden. Nothing to worry about. It will run in x8 if you have 2 graphics cards.

[GOD RAYS ON ULTRA™]

Your system information will tell you if it's running at optimal speed.

Top of this page. Click Help, then click System Information. Look at the log and see if it says PCIE 16X under Primary Bus.

[Overseer]

Originally posted by Ad Hominem:

Just by looking at the picture of the board on the linked website, the second slot says PCI 16_2, which would say to me that it's a PCIe 3 x16 lane slot, so you're golden. Nothing to worry about. It will run in x8 if you have 2 graphics cards.

I checked the manual and it looks like PCIE_X16_2 is a x16 in physical length, but technically a wired x4. There is actually no clear information about what happens if only PCIE_X16_2 is used.

[h_LordEC[no-VC]]

Originally posted by Overseer:

Originally posted by Ad Hominem:

Just by looking at the picture of the board on the linked website, the second slot says PCI 16_2, which would say to me that it's a PCIe 3 x16 lane slot, so you're golden. Nothing to worry about. It will run in x8 if you have 2 graphics cards.

I checked the manual and it looks like PCIE_X16_2 is a x16 in physical length, but technically a wired x4. There is actually no clear information about what happens if only PCIE_X16_2 is used.

I'm not sure but you are correct that the manual has a really convoluted way of describing their PCIe layout.

The part of the spec sheet says that there are two PCIe 3.0 x16 Safe Slots that "support x16, x8/x4 modes). Which, the way I read it, says single population of either slot it should be running at x16 mode. But when running a card in each slot, one will be x8 and the other in x4 modes.

[Turbo Soggy]

Originally posted by DudeSau©e™:

Your system information will tell you if it's running at optimal speed.

Top of this page. Click Help, then click System Information. Look at the log and see if it says PCIE 16X under Primary Bus.

Primary Bus: PCI Express 4x

Looks like it needs changed.

It's been running at x4. Is this bad for the card? Is it damaged now?