Aurora R12, PCIe 4.0 to 3.0

Question

How do I change the bus from PCIe 4.0 to PCIe 3.0? You lock down your BIOS that we cannot change advanced settings. Please let me know.

Vanadiel · Accepted Answer

4.0 is backwards and forwards compatible with 3.0. If you insert a 3.0 card it should automatically revert to 3.0 mode.

Based on the Aurora R12 service manual, there is not an option to set the operation of the PCIe slots from 4.0 mode to 3.0 mode. Service manual located here

What type of card are you trying to install?

r72019 · Accepted Answer

Yeah, the bios is limited unfortunately compared to aftermarket boards.

Vanadiel · Answer

I do not think you can. Is there a specific reason why you want to switch to 3.0?

drozek9898 · Answer

Because I have a PCIe 3.0 device and it doesn’t work when the bus is in 4.0 mode. Confirm on non dell systems.

drozek9898 · Answer

It doesn’t work, it is a pcie riser card

r72019 · Answer

Also note the aurora doesn't support bifurcation, so you'd likely need a card with a switch chip if you're splitting lanes as opposed to extending with a riser cable.

drozek9898 · Answer

No I haven’t why cannot I just change it in the bios and be done with it like every other manufacturer let’s me change it.

drozek9898 · Answer

I am not splitting lanes just moving them up.

drozek9898 · Answer

Looking for this support team to allow me to do this. Anyone from dell listening?

r72019 · Answer

Yeah, that could be an issue, have you tried getting a pcie 4.0 riser.

drozek9898 · Answer

Nope.

imirosav87 · Answer

I am having the same exact issue. Did you find a solution?

Alienware Desktops

Aurora R12, PCIe 4.0 to 3.0

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