I think you're off by a couple orders of magnitude there. 25e3 errors/(1e9 h * 1e6 b) = 25e-12 errors/hour/bit, ~~or 4 errors/hour/terabyte.~~ Edit: nope, I go

I think you're off by a couple orders of magnitude there. 25e3 errors/(1e9 h * 1e6 b) = 25e-12 errors/hour/bit, ~~or 4 errors/hour/terabyte.~~ Edit: nope, I got that last step wrong, it's actually 200 errors/hour/terabyte, or 1 error/gigabyte/5 hours, pretty close to what you said.