I have a question about the DFI LP LT XT X48-T2R motherboard.

It has 3 PCI-E lanes. According to the manual it can handle 2 GPUs at x16 and a x4 physics card. Could I put another card in the x4 such as a RAID controller or can I only put a physics card in? The manual I am reffering to is here on page 55 : http://www.dfi.com.tw/Upload/Manua [...] sh%202.pdf

Thanks!

you can use the PCI-e slot for whatever you want beit RAID controller, sound card, NIC, GPU. However, note some RAID controllers are compatible with some motherboards, you are best checking with the RAID cards mfg if you are conserned.