Unfortunately, the i7-3770K is the best processor that your motherboard can take. (Overclocking not supported on the motherboard) It is a Quad-Core, 8 Thread processor.  It is possible to do some gaming with it, but nothing hardcore with maximum quality graphics.  It's up to you whether you want to upgrade to the i7-3770K, although there may not be much of a performance difference. The i7-3770 has a base clock of 3.4GHz, while the K variant has a base clock of 3.5 GHz. They both can turbo up to 3.9 GHz.
i have  Dell Inc. 0M9KCM A01     (this motherboard)  which all i7 cpu i can use in it currently i use (i7 3770 cpu) so which all i7 cpus will works with this motherboard (Dell Inc. 0M9KCM A01)
doubt