PCI-E x16 and PCI-E 2 x16 are backward and forwards compatible. The graphics card I have was released in both PCI-E 1 x16 and PCI-E 2 x16 (but I accidently got a PCI-E 2 version of the card). Since it was released in both should I really see a performance problem if I use the PCI-E 2 x16 card in my PCI-E 1 x16 slot?

Nope, it'll work just the same.

I assume that card was only made in 2 revisions because of a incompatibility on newer boards with certain chipsets.

Great! I read all around and found what a lot of so called experts said but I just wanted somebody on here to give me a straight, knowledgeable answer.

Also I got to thinking. Some people might consider this a noob question {Laugh}.



I know it had two revisions of which I got the second. I believe that your assumption is correct.
BTW the card is a GeForce 8400 GS. I know nothing really modern or too fancy ,but at the moment it is all I need and can afford.

If it's a GeForce 8400 GS, then you won't see any performance impact switching from PCIe 2.0 to PCIe 1.0.
PCIe 1.0 x16 has 4 GB/s of bandwidth, enough for that (low-end and old) card.
PCIe 2.0 x16 would be quite and overkill for that card, since it has 8 GB/s of total bandwidth.

The card works great, performance wise. The reason I posted the question in the first place was because I read online in another forum where somebody was going on and on about how they got terrible performance on even old cards for some reason. I believe the person was going on about how all PCIe 2.0 cards when put in PCIe 1.0 slots would not work correctly and how the backwards and forwards capability was really a fraud. I had already made up my mind by that point that the card would work and wouldn't have any problems because of the bandwidth. But for the $35 I spent on the card I figured I had better get confirmation from a creditable source that the card would work with no problems. I got the card installed about half an hour after my last post yesterday. The card works great.

Just to clarify a bit, I didn't say it would have any problems with the bandwidth, I was just saying that 8 GB/s is a lot for that card, and 4 GB/s is enough.

I understood you. Perhaps I should also clarify, when I said "I had already made up my mind by that point that the card would work and wouldn't have any problems because of the bandwidth." I should have perhaps said, "I had already made up my mind by that point that the card should work and wouldn't have any problems with bandwidth". Anyway, thanks for you time, CaptainPeanut.

Hey, I just want to post a warning (from personal experience) for others who might make their way to this thread in the future. While most PCIe 2.0 cards will work fine in PCIe 1.0 slots, not all of them are compatible. For example, I bought this Adaptec 6805E SAS RAID controller (http://www.adaptec.com/en-us/products/controllers/hardware/sas/entry/sas-6805e/). Whenever I install it in a computer with PCIe 1.0 slots, this card causes the computer to freeze while POSTing, and the computer won't even make it to the BIOS screen. If the same card is installed in a PCIe 2.0 computer, the card works flawlessly.

Then again, this is a "professional-grade" RAID controller, so perhaps it is more picky about PCIe bus speed than most.

also I think some of the older desktop boards had issues with raid cards in the pci-e x16 slots.