Pci-express 2.0 Backwards Compatibility Confusion

[Adventure Man]

Hey guys, I have a question as to the backwards compatibility of pci-express 2.0 with the older pci-express 1.0a specification. My motherboard which I got a few days ago has the older 1.0a spec. My motherboard is a Biostar P4M900-M4 ver.6.x with latest Bios from this September. Here is the website for that motherboard: http://www.biostar.com.tw/app/en-us/mb/content.php?S_ID=283

I would like to purchase (and install on this motherboard) either an 8800GT,8800 GTS from nvidia or 3850,3870 from ati, all four of which use the new pci-express 2.0 specification and require motherboards with pci-express 2.0.
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10007125
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10007249
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10007405

I've heard so many conflicting reports, yes it is compatible, no they are not compatible etc.... Then I see some people whose older mobos with 1.0a specification worked with 2.0 video cards. AND I see some people whose older mobos with 1.0a did not work with an 8800GT. Can we just settle this issue with a simple yes/no or is the answer mobo specific, or is this just ultra complex?

Lastly, is it just a BIOS update that is needed to make these two specifications more compatible?

Thanks a bunch for your time guys.

A.M.

 

[esa193]

do bios update to be safe
and i havnt herd any probs
runs just fine

 

[Atomic Rooster]

PCIe 2.0 video cards are not fully backwards compatible. Graphic cards designed for v2.0 will work with v1.1 only. They will not work in v1.0 and v1.0a motherboards.



PCI Express 2.0 Wiki

 

[worshipme]

But almost all new mobos have PCI-E 1.1.

 

[esa193]

almost all mb have 1.1.....

 

[Adventure Man]

UPDATE:

I got an email from tech support at Biostar. The pci-express 2.0 video cards WILL NOT work on this particular motherboard. Stick with regular pci-express x 16.

A.M