To my knowledge the game only supports single and 2-WAY SLI or CF GPU's. Start by running the GCF Procedure for Call of Duty: Ghosts Multiplayer - Verify Game Cache Files (GCF) - How To's - Knowledge Base - Steam Support and if you modified your config_mp.cfg (Config file) or other files then restore those to their original state until the problem is identified and solved.
Thank you for posting your concerns!
Can you please post your dxdiag so we can know what your set up is? Also, let us know if you tried any of the steps provided by Momba1.