I have 77 HW for 20 minutes right now, with 22.5gh/s hashrate (calculated by pool).
So HW is really nothing important, I think.
(sourcecode say, HW is appear if calculated HASH have dufficult bigger that ASIC can calculate, so ASIC think this is error.. but really we can comment this check and send all hashes to pool, so pool himself will check is hash OK or reject it. I try this trick with qubit algo on D3, and really some hash was accepted by pool, and some rejected, but without comment this check all hashes was HW errored).