I'm trying to determine if this motherboard's bottom PCI-e slot runs at x16 speed or not.

https://www.newegg.com/asus-rog-strix-b650-a-gaming-wifi/p/N82E16813119606?item=N82E16813119606&source=googleshopping&nm_mc=knc-googleadwords-mobile&cm_mmc=knc-googleadwords-mobile-_-pla-_-motherboards+-+amd-_-N82E16813119606&utm_source=google&utm_medium=paid+shopping&utm_campaign=knc-googleadwords-mobile-_-pla-_-motherboards+-+amd-_-N82E16813119606&id0=Google&id1=19141281834&id2=141459484262&id3=&id4=&id5=pla-1837744399080&id6=&id7=9027669&id8=&id9=g&id10=m&id11=&id12=CjwKCAiAuOieBhAIEiwAgjCvcr6XnBKel7b1iF48FJRdEF5VgKjr8rRISyc2EZxqa9Lp_mlDy63zNRoC2v0QAvD_BwE&id13=Y&id14=Y&id15=&id16=639428055260&id17=&id18=&id19=&id20=&id21=pla&id22=8438988&id23=online&id24=N82E16813119606&id25=US&id26=1837744399080&id27=&id28=&id29=&id30=4045975527357345367&id31=en&id32=&id33=&id34=&gclid=CjwKCAiAuOieBhAIEiwAgjCvcr6XnBKel7b1iF48FJRdEF5VgKjr8rRISyc2EZxqa9Lp_mlDy63zNRoC2v0QAvD_BwE&gclsrc=aw.ds

The spec under Expansion Slots says:

Quote:

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1 x PCIe 4.0/3.0 x16 slot

AMD B650 Chipset
1 x PCIe 4.0/3.0 x16 slot (supports x4 mode)*

* PCIe 4.0 x16 slot (supports x4 mode) from AMD B650 Chipset shares bandwidth with M.2_3.

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The "supports x4 mode" is what is really throwing me off. Does that mean that's the highest speed in that slot or does it mean it runs at x4 when sharing bandwidth with M.2_3?

If you grab the manual from ASUS it should tell you.

stridulent said:

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I'm trying to determine if this motherboard's bottom PCI-e slot runs at x16 speed or not.

https://www.newegg.com/asus-rog-strix-b650-a-gaming-wifi/p/N82E16813119606?item=N82E16813119606&source=googleshopping&nm_mc=knc-googleadwords-mobile&cm_mmc=knc-googleadwords-mobile-_-pla-_-motherboards+-+amd-_-N82E16813119606&utm_source=google&utm_medium=paid+shopping&utm_campaign=knc-googleadwords-mobile-_-pla-_-motherboards+-+amd-_-N82E16813119606&id0=Google&id1=19141281834&id2=141459484262&id3=&id4=&id5=pla-1837744399080&id6=&id7=9027669&id8=&id9=g&id10=m&id11=&id12=CjwKCAiAuOieBhAIEiwAgjCvcr6XnBKel7b1iF48FJRdEF5VgKjr8rRISyc2EZxqa9Lp_mlDy63zNRoC2v0QAvD_BwE&id13=Y&id14=Y&id15=&id16=639428055260&id17=&id18=&id19=&id20=&id21=pla&id22=8438988&id23=online&id24=N82E16813119606&id25=US&id26=1837744399080&id27=&id28=&id29=&id30=4045975527357345367&id31=en&id32=&id33=&id34=&gclid=CjwKCAiAuOieBhAIEiwAgjCvcr6XnBKel7b1iF48FJRdEF5VgKjr8rRISyc2EZxqa9Lp_mlDy63zNRoC2v0QAvD_BwE&gclsrc=aw.ds

The spec under Expansion Slots says:

Quote:

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1 x PCIe 4.0/3.0 x16 slot

AMD B650 Chipset
1 x PCIe 4.0/3.0 x16 slot (supports x4 mode)*

* PCIe 4.0 x16 slot (supports x4 mode) from AMD B650 Chipset shares bandwidth with M.2_3.

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The "supports x4 mode" is what is really throwing me off. Does that mean that's the highest speed in that slot or does it mean it runs at x4 when sharing bandwidth with M.2_3?

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x4 is speed, 16x is physical slot size, that means it is capable of wiring up to 16 PCIe lanes, but on your motherboard for that slot, it only has 4 lanes connected to it. (4 lanes at x4 speed = x16 single lane equivalent). Plus your limited lanes are sharing bandwidth with your m.2 drive. So on heavy use for GFX, it might slow or fight for bandwidth with your hard drive(s).

FatZilla said:

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stridulent said:

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I'm trying to determine if this motherboard's bottom PCI-e slot runs at x16 speed or not.

https://www.newegg.com/asus-rog-strix-b650-a-gaming-wifi/p/N82E16813119606?item=N82E16813119606&source=googleshopping&nm_mc=knc-googleadwords-mobile&cm_mmc=knc-googleadwords-mobile-_-pla-_-motherboards+-+amd-_-N82E16813119606&utm_source=google&utm_medium=paid+shopping&utm_campaign=knc-googleadwords-mobile-_-pla-_-motherboards+-+amd-_-N82E16813119606&id0=Google&id1=19141281834&id2=141459484262&id3=&id4=&id5=pla-1837744399080&id6=&id7=9027669&id8=&id9=g&id10=m&id11=&id12=CjwKCAiAuOieBhAIEiwAgjCvcr6XnBKel7b1iF48FJRdEF5VgKjr8rRISyc2EZxqa9Lp_mlDy63zNRoC2v0QAvD_BwE&id13=Y&id14=Y&id15=&id16=639428055260&id17=&id18=&id19=&id20=&id21=pla&id22=8438988&id23=online&id24=N82E16813119606&id25=US&id26=1837744399080&id27=&id28=&id29=&id30=4045975527357345367&id31=en&id32=&id33=&id34=&gclid=CjwKCAiAuOieBhAIEiwAgjCvcr6XnBKel7b1iF48FJRdEF5VgKjr8rRISyc2EZxqa9Lp_mlDy63zNRoC2v0QAvD_BwE&gclsrc=aw.ds

The spec under Expansion Slots says:

Quote:

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1 x PCIe 4.0/3.0 x16 slot

AMD B650 Chipset
1 x PCIe 4.0/3.0 x16 slot (supports x4 mode)*

* PCIe 4.0 x16 slot (supports x4 mode) from AMD B650 Chipset shares bandwidth with M.2_3.

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The "supports x4 mode" is what is really throwing me off. Does that mean that's the highest speed in that slot or does it mean it runs at x4 when sharing bandwidth with M.2_3?

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x4 is speed, 16x is physical slot size, that means it is capable of wiring up to 16 PCIe lanes, but on your motherboard for that slot, it only has 4 lanes connected to it. (4 lanes at x4 speed = x16 single lane equivalent). Plus your limited lanes are sharing bandwidth with your m.2 drive. So on heavy use for GFX, it might slow or fight for bandwidth with your hard drive(s).

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Additionally, per the manual using PCIEx16_2 slot disables M.2_3.

Quote:

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AMD Ryzen 7000 Series Desktop Processors:
- M.2_1 slot supports PCIe 5.0 x4 mode M Key design and type 2242/2260/2280 storage devices.
- M.2_2 slot supports PCIe 4.0 x4 mode M key design and type 2242/2260/2280 storage devices.

AMD B650 Chipset:
- M.2_3 slot supports PCIe 4.0 x4 mode M key design and type 2242/2260/2280/22110 storage devices.

The M.2 SSD module is purchased separately.
AMD RAIDXpert2 Technology supports NVMe RAID 0, 1, and 10 configurations.
M.2_3 slot shares bandwidth with PCIEx16_2 slot (supports x4 mode). When PCIEx16_2 slot is operating, M.2_3 will be disabled.

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Thanks. I don't need to use my m2 in that slot, but it sounds like I can't put a GPU in there either.

stridulent said:

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Thanks. I don't need to use my m2 in that slot, but it sounds like I can't put a GPU in there either.

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Nothing prevents you from using a GPU in there. It should run just fine. x4 speed means its running 4 times faster to equalize as if it was running 16 individual lanes at 1x speed.

FatZilla said:

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stridulent said:

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Thanks. I don't need to use my m2 in that slot, but it sounds like I can't put a GPU in there either.

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Nothing prevents you from using a GPU in there. It should run just fine. x4 speed means its running 4 times faster to equalize as if it was running 16 individual lanes at 1x speed.

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I have this board now. Yes, the GPU works in that slot under normal Windows OS load. But if I try to play a game, I get some pretty severe frame drops. I'm hoping that there is a setting in the BIOS that may just need to be tweaked to enable full performance of the GPU in this slot, as it would be my preference, but I have not be able to find that setting.