Slow CD rips from 1633s?

I’m trying to use a 1633s to rip CDs with Eaxct Audio Copy and I get no better than 3.7x ripping speed. Using the Nero test tools provided with the drive I’m able to see a full 40x transfer rate, but using any other software the drive reads very slowly. The most notable difference I can observe between using EAC and Nero seems to be the speed the drive spins at, which with EAC is fairly slow while with Nero runs at full tilt.

Any clues as to what could be causing the extremely slow CD reads with EAC?