Bottom PCIe Slot not Working

[Zakk8]

I have a rtx 3090 and 3070. A Asus Rog strix b450f. I've done process of elimination, and even taken out the M.2, but the bottom slot just doesn't seem to work. I tested both cards on the top slots and both cards work I am sure that it is the mobo. Any thoughts?

[BiotechBen]

What cpu are you running? And most b450 boards unless you are running a 5000 series chip aren't going to support anything but 2x8 lanes each for two graphics cards. It should be in the BIOS to configure to 1x16, 2x8, or 4x4....

[svmlegacy]

17 minutes ago, Zakk8 said:

I have a rtx 3090 and 3070. A Asus Rog strix b450f. I've done process of elimination, and even taken out the M.2, but the bottom slot just doesn't seem to work. I tested both cards on the top slots and both cards work I am sure that it is the mobo. Any thoughts?

How is the BIOS configured? Do you have anything in PCIEX1_2 or PCIEX1_3? What CPU? APU's cannot utilize PCIEX16_2.

Check this setting in BIOS specifically:

[Zakk8]

9 minutes ago, BiotechBen said:

What cpu are you running? And most b450 boards unless you are running a 5000 series chip aren't going to support anything but 2x8 lanes each for two graphics cards. It should be in the BIOS to configure to 1x16, 2x8, or 4x4....

Since it's a mining setup, it's a ryzen 3 2200g

[svmlegacy]

4 minutes ago, Zakk8 said:

Since it's a mining setup, it's a ryzen 3 2200g

The Ryzen 3 2200G only has a PCIe x8 connection available, which the board allocates only to PCIEX16_1.

PCIEX16_2 is unavailable for use. There's nothing wrong with your hardware.

[Zakk8]

4 minutes ago, svmlegacy said:

How is the BIOS configured? Do you have anything in PCIEX1_2 or PCIEX1_3? What CPU? APU's cannot utilize PCIEX16_2.

Check this setting in BIOS specifically:

I will definitely look I to that in the bios. But even though it's an apu, I tested and an individual card in the bottom slot (pciex16_2),and it still didn't work with one gpu. 

[Zakk8]

1 minute ago, svmlegacy said:

The Ryzen 3 2200G only has a PCIe x8 connection available, which the board allocates only to PCIEX16_1.

PCIEX16_2 is unavailable for use. There's nothing wrong with your hardware.

Would the ryzen 5 2600 work? 

[BiotechBen]

The 2600 has 20 PCIe gen 3 lanes. With 2 3000 series Nvidia cards, of you want to really benefit from them, you need a better chip than a 2600.... Right now you have a serious bottleneck for the CPU. It would be like trying to drop a V12 in a honda civic....

[svmlegacy]

3 minutes ago, Zakk8 said:

Would the ryzen 5 2600 work? 

Yes. Any Ryzen CPU without a G (And obviously is supported by Asus) should allow the PCIEX16_2 to work.

PCIEX16_2 though, is in the middle of the board. Does PCIEX16_3 work?

[Zakk8]

2 minutes ago, svmlegacy said:

Yes. Any Ryzen CPU without a G (And obviously is supported by Asus) should allow the PCIEX16_2 to work.

PCIEX16_2 though, is in the middle of the board. Does PCIEX16_3 work?

Couldn't try because psu is blocking. 

[svmlegacy]

Just now, Zakk8 said:

Couldn't try because psu is blocking. 

That explains why you're calling #2 the bottom slot.

#3 should function in x2 or x4 mode, depending on BIOS setup. x4 or Auto mode will disable PCIEx1_2 & PCIEx1_3.

[Zakk8]

40 minutes ago, svmlegacy said:

That explains why you're calling #2 the bottom slot.

#3 should function in x2 or x4 mode, depending on BIOS setup. x4 or Auto mode will disable PCIEx1_2 & PCIEx1_3.

Just to confirm. If I get a ryzen 5 2600, I can put a 3090 in the top slot, and a 3070 in the second slot?