It's enough unless you prefer to have a quieter fan / cooler running CPU.
For example, I plan to buy one of Noctua's monsterous CPUs coolers so that I can cool a core i5-4670k (when I decide to buy it) simply because I want my PC to be quiet. When I move the i5-4670k into my HTPC case in 2016 (buying Intel's Skylake CPU), I will then remove the fans from the Noctua heatsink so that it can passively cool an underclocked i5-4670k. I like for my HTPC to be extremely quiet.