Bun is Slower than Node with Recursive Negamax Function.

[eli-rich]

What version of Bun is running?

0.2.2 (canary)

What platform is your computer?

Darwin 21.6.0 Darwin Kernel Version 21.6.0: Sat Jun 18 17:07:25 PDT 2022; root:xnu-8020.140.41~1/RELEASE_X86_64 x86_64 i386

What steps can reproduce the bug?

To replicate:

1. Clone this repo.
2. bun install
3. time node index.js
4. time bun index.js
5. Compare results.

The relevant code comes from my npm package.

It uses the negamax algorithm to find the best move in a tic-tac-toe game.

function negamax(board: Board, depth: number, alpha: number, beta: number): number {
  if (board.isOver || depth === 0) {
    if (board.winner === -1) return 0;
    else {
      return board.winner === board.turn ? 100 : -100;
    }
  }
  let bestScore = -Infinity;
  for (const move of board.moves) {
    board.move(move);
    const score = -negamax(board, depth - 1, -beta, -alpha);
    board.undo(move);
    bestScore = Math.max(score, bestScore);
    alpha = Math.max(alpha, score);
    if (alpha >= beta) break;
  }
  return bestScore;
}

Here is the full code from the benchmark:

import { Board, search } from 'exesjs';

for (let i = 0; i < 10; i++) {
  console.time('game');
  const board = new Board({
    width: 6,
    height: 6,
    winLength: 4,
    turn: 1,
  });
  while (!board.isOver) {
    board.move(search(board, 5));
    board.move(search(board, 5));
  }
  console.timeEnd('game');
}

How often does it reproduce? Is there a required condition?

It is consistently slower than node.js

What is the expected behavior?

Expected behavior is to have similar performance to node.js

What do you see instead?

Here are the logs from macOS 12.5 and elementaryOS 6.1:

elementary OS 6.1 (old gaming pc):

1. NODEJS:

   game: 2.372s
   game: 2.963s
   game: 1.845s
   game: 3.067s
   game: 5.448s
   game: 6.176s
   game: 1.561s
   game: 2.593s
   game: 1.514s
   game: 2.434s
   node index.js  30.08s user 0.05s system 100% cpu 30.029 total

2. BUN:

   [5.28s] game
   [7.16s] game
   [7.65s] game
   [9.20s] game
   [16.72s] game
   [5.67s] game
   [8.17s] game
   [9.73s] game
   [9.32s] game
   [8.84s] game
   bun index.js  88.00s user 0.15s system 100% cpu 1:27.76 total

macOS Monterey 12.5 (macbook pro 2020 intel i5):

1. NODEJS:

   game: 3.601s
   game: 7.024s
   game: 4.469s
   game: 6.390s
   game: 6.889s
   game: 5.371s
   game: 2.786s
   game: 3.324s
   game: 1.901s
   game: 4.944s
   node index.js  44.52s user 1.02s system 96% cpu 47.337 total

   2. BUN:

      [8.10s] game
      [12.46s] game
      [7.34s] game
      [11.05s] game
      [6.68s] game
      [7.53s] game
      [10.47s] game
      [8.93s] game
      [7.46s] game
      [3.20s] game
      bun index.js  81.48s user 1.53s system 99% cpu 1:23.26 total

Additional information

I created a github repo to easily replicate this.

https://github.com/BlazingFire007/bun-benchmark-negamax

[eli-rich]

To be clear I had the same results on my old gaming PC running elementary OS 6.1.

The results of that test are included.