From their benchmarks rietveld: $ ./perf.py -r -b rietveld --args "-j always," --track_memory ../q2/python ../q3/python Mem max: 575116.000 -> 55952.000: 927.87% smaller

This 930% basically means that 2009Q3 can use as little as ~1/10 of the memory of 2009Q2.