PCI x16 and x4 crossfire

[fugben]

I guys i have a radeon 6870, phenom 2 1090T and this motherboard:

MSI 870-G45 AM3 AMD 770 ATX AMD Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130290

It has 2 PCI 2.0 slots but one is 16 x and the other is 4x

I am looking to add another 6870 for crossfire.

Would the 4x bottleneck badly?

 

[Maziar]

For PCI-E 1.0 cards, x4 will definitely hurt the performance but for PCI-E 2.0 cards, there isn't much of a difference between x16x4 and dual x16/x8 speed.