You'd be on the cusp of thermal throttling if you tried to run super-CPU-heavy stuff or torture-test it. Mine already barely kept my 4790k at like 95C on the hottest core, although that may also have been partly due to user error.
Just a heads up, the included fan, although extremely quiet during operation, is kinda crap at being... a fan. Mine also had some kind of manufacturing defect, so the faster it spun, the more out of true it spun, resulting in this horrible oscillating noise, kind of like leaving the window down while driving down the highway, from the imbalance/imperfection that I couldn't find. Replaced the stock fan with a Darksider GT, temps dropped by about 5-10C under load.
At $40~ish, it's not bad to have on hand should your water cooling solution fail for some reason *hint hint*.