Well, I have confirmed with someone still working at my former employer that a DBCC CHECKDB job I set up to run overnight on a 1TB+ production database shows recent run times of 4.5 to 4.8 hours.

Too bad I may have blown an interview because the interviewer was unaware that DBCC CHECKDB runs against a hidden snapshot to avoid lock-related performance issues and believed it was impossible to run DBCC CHECKDB on a 1TB database in less than 5 hours.