There's a high probably of a bottleneck but even a "worst case scenario" it won't surpass a 15% bottleneck. I would OC your CPU to 3.0GHz and get a Cool Master Hyper 212+ CPU Cooler - Economical cooler with a "true and tested" design.
ok great even i have a gigabyte mobo so shouldnt be too much of a problem upping your cpu clock... please list the rest of your config as well for me to get a better idea for helping you on ur overclock