c:\test>each-keys-b -M1=keys -M2=pairs -N=1e6
hash built, starting timer
Took 11.663000 and 56.145MB extra memory for 1000000 using keys/pairs method

c:\test>each-keys-b -M1=each -M2=pairs -N=1e6
hash built, starting timer
Took 1.296000 and 0.020MB extra memory for 1000000 using each/pairs method