Is NodeJs faster than Clojure?

Question

I just started learning Clojure. One of the first things I noticed is that there are no loops. That's OK, I can recur. So let's look at this function (from Practical Clojure):

(defn add-up   "Adds up numbers from 1 to n"   ([n] (add-up n 0 0))   ([n i sum]      (if (< n i)       sum       (recur n (+ 1 i) (+ i sum))))) 

To achieve the same function in Javascript, we use a loop like so:

function addup (n) {   var sum = 0;   for(var i = n; i > 0; i--) {     sum += i;   }   return sum; } 

When timed, the results look like:

input size: 10,000,000 clojure: 818 ms nodejs: 160 ms  input size: 55,000,000 clojure: 4051 ms nodejs: 754 ms  input size: 100,000,000 clojure: 7390 ms nodejs: 1351 ms 

I then proceeded to try the classic fib (after reading this):

in clojure:

(defn fib   "Fib"   [n]   (if (<= n 1) 1       (+ (fib (- n 1)) (fib (- n 2))))) 

in js:

function fib (n) {   if (n <= 1) return 1;   return fib(n-1) + fib(n-2); } 

Again, the performance has quite some difference.

fib of 39 clojure: 9092 ms nodejs: 3484 ms  fib of 40 clojure: 14728 ms nodejs: 5615 ms  fib of 41 clojure: 23611 ms nodejs: 9079 ms 

Note I'm using (time (fib 40)) in clojure so it's ignoring the bootup time for JVM. These are ran on a MacBook Air (1.86 Ghz Intel Core 2 Duo).

So what's causing Clojure to be slow here? And why do people say that "Clojure is fast"?

Thanks in advance and Please, no flame wars.

Answer 1

(set! *unchecked-math* true)  (defn add-up ^long [^long n]   (loop [n n i 0 sum 0]     (if (< n i)       sum       (recur n (inc i) (+ i sum)))))  (defn fib ^long [^long n]   (if (<= n 1) 1       (+ (fib (dec n)) (fib (- n 2)))))  (comment   ;; ~130ms   (dotimes [_ 10]     (time      (add-up 1e8)))    ;; ~1180ms   (dotimes [_ 10]     (time      (fib 41)))   ) 

All numbers from 2.66ghz i7 Macbook Pro OS X 10.7 JDK 7 64bit

As you can see Node.js is trounced. This is with 1.3.0 alphas, but you can achieve the same thing in 1.2.0 if you know what you're doing.

On my machine Node.js 0.4.8 for addup 1e8 was ~990ms, for fib 41 ~7600ms.

            Node.js  | Clojure                      |  add-up       990ms  |   130ms                      |  fib(41)     7600ms  |  1180ms