I had replaced the stock cooler on my i7-4771 with a Noctua NH-L12 and, after also tuning the BIOS of my Intel DQ87PG motherboard to cool more aggressively, it keeps the temperatures around 58-59 degrees (Celsius) while running Prime95, so under full load. Lower temperatures means longer CPU life, no matter what Intel says. The Noctuas are also very silent fans. You get what you pay for. The stock cooler is fine for most people, but I simply throw it away.