TL;DR: The WD62PURZ has a better transfer rate and higher power consumption, probably thanks to a larger cache.

The WD62PURZ spins a little slower than the WD60PURZ, but it has a larger cache. Normally, a higher cache is a sign of an SMR drive, but WD gives no indication of which recording technology both drives use (CMR or SMR).

WD62PURZ specifications are very very close to the newer WD84PURZ- cache, power consumption , weight, MTBF. These are the only 2 drives in Purple product range to use a 5640 RPM spin speed.