* One PCI Express* x16 bus add-in card connector
* Two PCI Express* x1 bus add-in card connector
* One PCI Conventional* bus connector
Your GPU requires PCI Express 2.0.
However, the PCI Express 2.0 standard states,
"PCI Express 2.0
PCI-SIG announced the availability of the PCI Express Base 2.0 specification on 15 January 2007. PCIe 2.0 doubles the bus standard's bandwidth from 0.25 GByte/s to 0.5 GByte/s, meaning a ×32 connector can transfer data at up to 16 GByte/s for both videocards (SLI 2×, etc.). PCIe 2.0 has two 32-bit channels for each GPU (2×16), while the first version only has 1×16 and is operating at 2 GHz.
PCIe 2.0 motherboard slots are backward compatible with PCIe v1.x. PCIe 2.0 cards have good backward compatibility, new PCIe 2.0 graphics cards are compatible with PCIe 1.1 motherboards, meaning that they will run on them using the available bandwidth of PCI Express 1.1. Overall, graphic cards or motherboards designed for v 2.0 will be able to work with the other being v 1.1 or v 1.0."
If it runs, it will run half as fast as it should.
That doesn't mean it will run "half as fast"; it means that the bandwidth (communication speed) will be theoretically half; cards today (anything not crossfired or sli'ed and nvidia 2xx series and amd hd4xxx series) dont use all that bandwidth anyway.
Bottom line it will work to the cards full potential,