PCI Express Version of the nVidia 650SLI Chipset

[pennstater]

I have a Gigabyte GA-N650SLI-DS4 Rev1 motherboard with the 650SLI chipset (c55 northbridge). I am interested in getting an MSI R5770 Hawk GPU (or something similar), but have read that the card may not work with the older PCI-E versions (1.0 and/or 1.0a). I am trying to determine which PCI-E revision my motherboard is using. Anybody have any clues? Anybody running a Radeon 5000 series GPU on this chipset (or even a 680)? Thanks.

 

[Henry Chinaski]

The PCI-e 2.0 is backward compatible with 1.0. There is no problem.

 

[pennstater]

I've read that too (the PCI-E spec is backwards compatible). I was just curious as I have read that there may be issues (my source is from user comments on the "Egg" which is "New" - I personally don't trust every comment there, but just wanted to make sure). Here is the comment...

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.

This person's motherboard make and model was not mentioned. I don't know, am I worrying about this too much?

 

[pennstater]

Well, I did a lot of digging came up with the following...

The 650i SLI chipset is comprised of the C55 northbridge chip and the MCP51 southbridge chip. Based on my understanding, the northbridge chip controls (for the most part) the PCI-E lanes, so I focused my attention on the C55.

After much Googling, I found a listing on the PCI-SIG's website about an "integrators list." It is broken out by PCI-E version; 1.0a/1.1 and 2.0. The links for each are below.

The C55 chipset is listed on the "PCI Express® 1.0a/1.1 Integrators List" but not on the "PCI Express® 2.0 Integrators List."

Also, most of my reading seems to show that if a chipset is PCI-E 1.x, then it simply lists the "feature" as "PCIe x16," for example. If it is 2.0 compliant, then it seems to be shown as "PCIe 2.0 x16." Not sure if this is a generalization or not, but I think this and the below pages from PCI_SIG are telling me that the PCI Express version of my motherboard is 1.x.

I also did a Google search on "5770 pci express issues" and there are folks out there reporting problems. Thing is, it might be hit and miss. I also read that the PCI-E spec states that backwards compatibility is possible, but add-on card manufactures can choose to offer it or not. Not sure how tru that is (it came from another forum).

Anyway, not sure what to do at this point. Don't want to upgrade the motherboard yet just to run a newer videocard. If the whole backward compatibility thing not being implemented by ATI is true, then that really sucks. I wonder if nVidia's new Fermi-based cards will have this issue (although I am not too keen on these from the early reviews).

Thoughts???



PCI-E 2.0

PCI-E 1.x