You don't need to Memoize fib_memo(), the memoisation is already built in! That's what the state variable %memo is for.

Once you remove that, the real performace shows up (This is for (1..100)): 

c:\test>junk21
Benchmark: timing 10000 iterations of Memo, Normal...
      Memo:  1 wallclock secs ( 0.64 usr +  0.00 sys =  0.64 CPU) @ 15
+649.45/s (n=10000)
    Normal: 15 wallclock secs (14.98 usr +  0.01 sys = 14.99 CPU) @ 66
+7.07/s (n=10000)

[download]

The difference is all the clearer with my preferred cmpthese() (why do you use timethese()?): 

c:\test>junk21
          Rate Normal   Memo
Normal   669/s     --   -96%
Memo   15573/s  2229%     --

[download]

In reply to Re^4: fibonacci numbers using subroutine? by BrowserUk
in thread fibonacci numbers using subroutine? by derpp

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