Maybe you have a bad chip or bad airflow? My 4770k never has dipped below 3.5
It actually regularly sits at 3.8+ for some reason.
This is why we don't judge off one chip but off reviews /batches of chops.
I'm on stock cooling as well.
I got two large fans spinning air out of the case (case has special vents for this), flow shouldnt be a problem.
While I only have *personal* experience with one haswell chip, these stories are not hard to find, we have had a few here alone and I suspect the reason why not more is hitting the issue is because they're not running heavy avx loads and not using the stock cooler. I can game on this thing for hours and never throttle, last i checked temps were around 75ish, however load up the avx2 version of prime95, let it run for 10-15 minutes and bang.. throttle time.
I'm sure you've checked already, but that sounds more like an issue with the HSF mount than an issue with the processor.
At stock configuration (Vcc, etc) with stock cooling, your 4770 should have no problem sustaining full-load at stock clockspeed indefinitely.
If it doesn't, then you should seek to RMA it the same as you would any other sub-par product.
What you describe is definitely not what Intel expects the product to perform like, something has gone awry and you shouldn't settle for it as is.
- Yea I would problary do that IF i wouldnt be without a CPU for the duration AND if I didnt get the impression that the fault is rather generic. The cure is simple, just dont run the avx2 version of prime95 (or any other avx heavy app im sure) and its good to go.
As for the hsf mount, other than the avx scenario temps looks to be in range with everyone else running stock.