Benchmark: typed array copyWithin vs set

Script Preparation code:

var array1_1e6 = Float32Array.from({length: 1e6}, Math.random);
var target = 1e5;
var start = 2e5;
var end = 3e5;
var array1_1e5 = Float32Array.from({length: 1e5}, Math.random);
var array2_1e5 = Float32Array.from({length: 1e5}, Math.random);

Tests:

set
array1_1e5.set(array2_1e5);
copyWithin
array1_1e6.copyWithin(target, start, end);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
set
copyWithin

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
set	77931.8 Ops/sec
copyWithin	76553.1 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net!

**What is being tested?**

The provided JSON benchmark compares the performance of two approaches: `set` and `copyWithin` methods for setting elements in typed arrays.

**Options compared:**

1. **`array1_1e5.set(array2_1e5)`**: This method sets all elements in `array1_1e5` to the values in `array2_1e5`.
2. **`array1_1e6.copyWithin(target, start, end)`**: This method copies elements from `array2_1e6` to `array1_1e6` starting at index `target` and ending at `end`.

**Pros and Cons of each approach:**

**`set`:**

Pros:

* Easier to read and understand
* Can be more efficient for small arrays

Cons:

* Requires creating a new typed array, which can lead to slower performance for large arrays due to memory allocation

**`copyWithin`:**

Pros:

* Avoids creating a new typed array, reducing memory allocation overhead
* Can be faster for larger arrays since it only copies elements, not allocates new space

Cons:

* May have additional overhead due to indexing and bounds checking

**Library usage:**
The benchmark uses the `Float32Array` constructor from the JavaScript built-in types. This is a typed array that stores 32-bit floating-point numbers.

**Special JS features or syntax:**

None explicitly mentioned, but it's worth noting that both methods use arrays as input and output, which is a common pattern in JavaScript.

**Benchmark preparation code explanation:**

The script prepares two large typed arrays (`array1_1e5` and `array2_1e5`) using the `Float32Array.from()` method. It then defines some constants for indexing and execution timing (start and end times).

**Individual test cases:**

Each test case represents a separate benchmark:

* **"set"`**: This benchmark calls `set()` on `array1_1e5` with `array2_1e5` as its argument.
* **"copyWithin"`**: This benchmark calls `copyWithin()` on `array1_1e6` with indices `target`, `start`, and `end`.

**Latest benchmark result:**

The latest results show that the `set()` method performed slightly faster than `copyWithin()` in this specific test case. However, note that these results may vary depending on the system configuration and browser version.

Other alternatives for testing typed array operations might include:

* Using other types of arrays (e.g., `Int32Array`, `Uint8Array`)
* Adding more test cases with varying input sizes or complexity
* Comparing performance against other libraries or frameworks that implement similar functionality

Related benchmarks:

typed array copyWithin vs set (version: 0)

comparing speed of copyWithin vs set

Comparing performance of: set vs copyWithin

Created: 3 years ago by: Registered User

Jump to the latest result

set

copyWithin

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):