rtx titan

Hello! I am wanting to upgrade my Optiplex 990 MT, which has a 6D7TR motherboard and an i5 2400. I am wanting to get a RTX TITAN, but I am assuming my CPU would bottleneck it. A foreign sight says that the motherboard's best CPU is the i7 2600, but I can't find anything official. Anything?

Hi guys I am building a gaming rig and i can’t choose between these gpu’s. I basically need the best gaming gpu on the market and its either the TI or the titan. I am leaning more to the titans side but i am not sure if its actually any better? You need to look at this from a performance stand...