CMU has always been harsher and more unforgiving than MIT.
For the cohort entering 2006, MIT's 6-year graduation rate was 92% for men, 93% for women. CMU's was 85% for men and 90% for women. CMU's entering class of 2011 first-year attrition rate was 5%. MIT's was 3%. MIT's 4-year graduation rate is 85% versus 71% for CMU.