It will work, but you have choices based on the following.
If you are using a dedicated GPU, I would return the Revo and go with SSD's, keeping the PCIe_1 x16 slot for full speed graphics.
If not, you can put the Revo in the lower PCIe_2 x8 slot. This will allow you to put a GPU in the upper slot, keeping in mind you will only get Gen 2 8x performance from the top slot as the bandwidth is shared.
There is no significant difference between Gen2 Gen3 performance on a x16 slot. Any Gen between x8 or x16 would matter from a performance standpoint.
1 x PCI Express x16 slot, running at x16 (PCIEX16)
* For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.
1 x PCI Express x16 slot, running at x8 (PCIEX8)
* The PCIEX8 slot shares bandwidth with the PCIEX16 slot. When the PCIEX8 slot is populated, the PCIEX16 slot will operate at up to x8 mode.
3 x PCI Express x1 slots
(All PCI Express slots conform to PCI Express 2.0 standard.)
2 x PCI slots
So the choice is yours. What the goal is and the primary use for the system. Others may have more to add.
