Possible to spilt one PCIe 16x endpoint into 2 PCIe 8x endpoint?

[Vienna]

I'm curious if its possible to have a PCIe riser that splits it into 2 8x electrical slots?

I'm not entirely sure how PCIe endpoints work so I could be completely off base but I don't see why it couldn't be possible.

[chris.y2k.r1]

I doubt it, there's logic in the SB that tells the board what speeds to run what ports at. I can't see how an add-on riser would be able to tell the Mobo to see 2 channels on 1 bus and run them at 8x instead of 16....

I'm not positive but I don't think that a simple riser could do the job.