Benchmark: EcmaScript6 Int16Array vs regular JS array

Script Preparation code:

var int16 = new Int16Array(100);
var regular = [];

for(var i=0;i<100;i++){
  int16[i] = i;
  regular.push(i);
}

Tests:

Int16Array
var sum = 0; for(var i=0;i<100;i++){ sum = sum + int16[i]; }
Plain JS array
var sum = 0; for(var i=0;i<100;i++){ sum = sum + regular[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Int16Array
Plain JS array

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/136.2 Mobile/15E148 Safari/605.1.15

Browser/OS: Mobile Safari 18 on iOS 18.3.2

View result in a separate tab

Test name	Executions per second
Int16Array	18292002.0 Ops/sec
Plain JS array	13614179.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested, compared, and other considerations.

**Benchmark Overview**

The benchmark compares the performance of two approaches:

1. **Int16Array**: Using a typed array (`Int16Array`) to store integer values in JavaScript.
2. **Plain JS array**: Using a regular JavaScript array to store integer values.

Both approaches have their own pros and cons, which we'll discuss below.

** Typed Array (Int16Array)**

*   Purpose: `Int16Array` is a typed array that stores 16-bit integers. It's designed for performance-critical applications where memory allocation and deallocation can be expensive.
*   Library: The JavaScript built-in typed arrays are implemented in the ECMAScript specification, which means they're part of the language standard.

** Regular JS Array**

*   Purpose: A regular JavaScript array is a dynamic data structure that can store any type of value, including integers. It's often used when flexibility and ease of use are more important than raw performance.
*   Library: The `Array` constructor and its methods (like `push`, `indexOf`, etc.) are part of the JavaScript language.

**Comparison**

In this benchmark, both approaches have a single loop that iterates over an array of 100 elements, performing some basic arithmetic operation. The key differences between the two approaches lie in:

*   **Memory allocation and deallocation**: When using `Int16Array`, memory is allocated once for the entire array, which can be beneficial for performance-critical applications. In contrast, regular JavaScript arrays allocate memory dynamically on each push operation.
*   **Type safety**: Using `Int16Array` ensures that only integers are stored in the array, whereas regular arrays allow storing any type of value.

**Pros and Cons**

*   **Typed Array (Int16Array)**:
    *   Pros:
        +   Better performance due to reduced memory allocation and deallocation.
        +   Improved cache locality.
    *   Cons:
        +   Requires careful handling of typed array operations, as they may not work like regular arrays.
        +   Limited flexibility compared to regular JavaScript arrays.
*   **Plain JS array**:
    +   Pros:
        - More flexible and easier to use than typed arrays.
        - No need for explicit type declarations or casting.
    *   Cons:
        - May incur higher overhead due to dynamic memory allocation and deallocation.

**Considerations**

When choosing between these two approaches, consider the following factors:

*   **Performance-critical applications**: If you're working on a project that requires raw performance, using `Int16Array` might be a good choice.
*   **Flexibility and ease of use**: For projects where flexibility and ease of use are more important than raw performance, regular JavaScript arrays might be a better fit.

**Alternatives**

If you need to compare performance between different data structures in JavaScript, here are some alternatives:

1.  **Big Int**: A built-in data structure for arbitrary-precision integers.
2.  **Float64Array**: A typed array for floating-point numbers.
3.  **Uint8ClampedArray`: A typed array for unsigned 8-bit integers with a specific set of limitations.

Each of these alternatives has its own use cases and performance characteristics, so be sure to consider them when making your decision.

In the provided benchmark result, we see that both approaches have relatively similar execution times, indicating that neither approach offers a significant advantage over the other in this particular test case.

Related benchmarks:

EcmaScript6 Int16Array vs regular JS array (version: 0)

Comparing performance of: Int16Array vs Plain JS array

Created: 8 years ago by: Registered User

Jump to the latest result

Int16Array

Plain JS array

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):