Lyra2v2 is problematic for nvidia, the miner itself reports 30% higher hashrate than actual. Perhaps you should add a penalty for the algorithm on nvidia or check what miner gives a real hashrate.
Weird, mine typically reports at the pool about what my miner is telling me it is. Mine say 55mh/s and typically reports between 45 and 65 (sometimes even higher in periods of good luck) at the pool.