kitsunestarwind :
You do not NEED to buy a aftermarket cpu cooler, stock coolers are designed to run the CPU they come with at standard speeds fine.
Aftermarket cpu coolers are needed if you plan on overclocking or need better cooling performance
It is true halfway. Yes they are designed to run just fine for stock speeds. But, they are not designed to run silent or to cool the cpu more. Under load, stockcooler noise can be disturbing. Plus when hyper threading and turbo on under full load, stock coolers fail to drop cpu temps. I remember I was reaching 100C easily with stock cooler when turbo mode is on @stock frequency and running prime95 stress test.
As a general sense if you use stock cooler, you should not be doing any overclocking at all.
As a general sense if you are going to mildly-casually overclocking you should go for aftermarket air cooling.
As a general sense if you aim to push the cpu to its limits you definitely need water cooling.
I'd suggest if you have spare 20-30$ buy a nice/cheap/effective air cooler and get rid of stock cooler...
Preferably Hyper 212 Evo for todays standards. Comes for like 25$. It makes a difference lol
But there are even cheaper solutions for like 15$ you can get a Zalman Performa
etc...