PCI Express 2.1 x16 Compatibility

Apr 2, 2011

I have a Dell Inspiron 580s, which I believe has a PCI Express 2.0 x16 slot. The video card I'm looking at getting (http://www.newegg.com/Product/Product.aspx?Item=N82E16814150447) says the interface is PCI Express 2.1 x16. Does this mean it will not work with my computer? Also, my power supply isn't gonna cut it. What's a reliable psu manufacturer? Thanks for reading.


Mar 5, 2009
He said SOME don't work, and he is right. This usually only happens on an OEM board that hasn't had a BIOS update in a long time. Also it is quite rare, but it does happen. If you only have a 1.0 slot, you're better off using a 2.0 card than a 2.1 card.


Your same link.

PCIe 2.0 motherboard slots are fully backward compatible with PCIe v1.x cards. PCIe 2.0 cards are also generally backward compatible with PCIe 1.x motherboards, using the available bandwidth of PCI Express 1.1. Overall, graphic cards or motherboards designed for v 2.0 will be able to work with the other being v 1.1 or v 1.0.
Generally means usually, but not always. It wasn't even until the 2.1 cards found in the AMD 5 series that people started complaining a lot about a lack of compatibility. Here are some real life reviews.


Cons: Do your research! It does not work with all MOBO's. After installing my computer didn't boot. When I pulled the card off, everything was fine. PSU is 500W. As you can find on different forums, there seems to be an issue with the PCI-e. It should be compatible from the cards 2.1 to 1 but for some MOBO's, like mine, it just don't work.

Apparently this card is not compatible with PCI Express 1.0, or at least it wasn't at all for me and my motherboard (Asus P5N-MX). Would get stuck in an endless reboot loop everytime I started the PC
If it helps to think of it like another problem, its like that issue with Via chipsets and SATA 3.0 drives. (KT600 and 800 for sure, I'm not positive about the KT880.) No matter what you do, you can't get a SATA 3.0 drive to work on their ports, even if its jumpered for 1.5 operation. It should, but it doesn't.


It has to do with PCIe as it was another example of something that should work but didn't.

I can see your in argumentative mode again, so I'm done with you yet again. Two people have tried to explain that its POSSIBLE, and you don't seem to listen. I linked first hand accounts, and you completely ignored. Someday I really wish you'd learn to accept that its possible you could actually learn something.


basically all pcie should be backwards compatable, even 2.1 in 1.x slots. The only incompatabilities are some really old pcie 1.0 motherboards and its not a slot incompatability its a BIOS incompatability. Any motherboard that has a BIOS release in the last couple years should be compatable. If it doesnt work you can take it back because the specs on a video card box clearly state "pcie slot" it does not specify any particular version.

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