I doubt they're faulty, but yes they aren't running at the advertised spec. But surely it would take longer to return it and wait for it to come back than it would be to change a few BIOS options and run a couple of tests. And you could probably get it to run faster than they could as you would have more time to dedicate to it.
As for the high PWM temp, that can be caused by a few things, bad airflow being the main culprit.