  Nonequilibrium information thermodynamics determines the minimum energy
dissipation to reliably erase memory under time-symmetric control protocols. We
demonstrate that its bounds are tight and so show that the costs overwhelm
those implied by Landauer's energy bound on information erasure. Moreover, in
the limit of perfect computation, the costs diverge. The conclusion is that
time-asymmetric protocols should be developed for efficient, accurate
thermodynamic computing. And, that Landauer's Stack -- the full suite of
theoretically-predicted thermodynamic costs -- is ready for experimental test
and calibration.
