3 ms·

C (gcc 4.2.1) 2.62 +/- 0.24 1.0x NaCl (x86-32) 3.39 +/- 0.25 1.3x asm.js (Firefox Nightly) 5.12 +/- 0.59 1.9x NaCl is 30% slower, asm.js is 90% slower.

• lutusp 13y ago
  Your conclusion doesn't follow from your data. 5.12 is not 90% slower than 2.62, it's 51% slower.
  • chr1 13y ago
    He says NaCl is 30% slower than _c++_, asm.js is 90% slower than _c++_ which is correct.
    • lutusp 13y ago
      For asm.js to be 90% slower than c++, it would have to run at 10% the speed of c++, not 51% of its speed, which is what the data shows. 100% slower is not 1/2 the speed, it's no speed at all. Take some speed x. Increasing it by 100% gives 2x. Decreasing it by 100% gives zero. Expressed another way, 100% of x is x. Add 100% = 2x, Subtract 100% = zero. The original claim is "90% slower." Clearly the OP either meant 51% slower or 49% slower, depending on how one reads it. a = 2.62 b = 5.19 a / b = 0.5048, or 50.48%: "b has 50.48 percent the speed of a". EDIT: wow, once again downvoted for being right and proving it.
      • jules 13y ago
        English conventions are inconsistent. "X is 2x slower than Y" usually means that Y runs at twice the speed of X. Since 90% = 0.9, "X is 90% slower than Y" would mean that X is actually faster than Y. Therefore it's better to state it in an unambiguous way, e.g. X took 2x as much time as Y, or just look at the numbers directly.
        • lutusp 13y ago
          > English conventions are inconsistent. Yes, and it's an argument for expressing these ideas with mathematics instead of words. > Therefore it's better to state it in an unambiguous way, e.g. X took 2x as much time as Y, or just look at the numbers directly. Complete agreement.