<p>Yes, it is unusually high, but I can confirm that it is an accurate workload: I’m taking CS 70 with Sahai right now and I consider myself to have an above-average math background (A in Math 54). Often I’ll spend less than 20 hours (14 hours perhaps) / week on CS 70, but other times, on weeks where we don’t have a midterm, I will hit the 20 hour limit.</p>