Benchmark: soa vs aos - MeasureThat.net

Script Preparation code:

var N = 1000000;

var x = [], y = [], z = [];

var xt = new Float32Array(1000000);
var yt = new Float32Array(1000000);
var zt = new Float32Array(1000000);

var vectors = [];

for(var i = 0; i < N; i++){
  x[i] = Math.random();
  y[i] = Math.random();
  z[i] = Math.random();
  
  xt[i] = x[i];
  yt[i] = y[i];
  zt[i] = z[i];
  
  vectors[i] = { x: x[i], y: y[i], z: z[i] };
}

var vector;

Tests:

soa
for (var i = 0, li=x.length; i < li; ++i) { x[i] = 2 * x[i]; y[i] = 2 * y[i]; z[i] = 2 * z[i]; }
aos
for (var i = 0, li=vectors.length; i < li; ++i) { vector = vectors[i]; vector.x = 2 * vector.x; vector.y = 2 * vector.y; vector.z = 2 * vector.z; }
soa mark II
for (var i = 0, li=x.length; i < li; ++i) { xt[i] = 2 * xt[i]; } for (var i = 0, li=x.length; i < li; ++i) { yt[i] = 2 * yt[i]; } for (var i = 0, li=x.length; i < li; ++i) { zt[i] = 2 * zt[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
soa
aos
soa mark II

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; rv:139.0) Gecko/20100101 Firefox/139.0

Browser/OS: Firefox 139 on Windows

View result in a separate tab

Test name	Executions per second
soa	88.3 Ops/sec
aos	123.1 Ops/sec
soa mark II	290.9 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 benchmark analysis.

**Benchmark Definition**

The benchmark is comparing two approaches to scaling out a loop: **Single-Assignment Optimization (SOA)** and **Arrays of Structures (AoS)**. In SOA, each iteration modifies a single variable that is assigned a new value in the next iteration. In AoS, each iteration works on an entire structure (in this case, an object with three properties) and assigns it to a temporary variable.

**Benchmark Preparation Code**

The preparation code creates four arrays: `x`, `y`, `z` (with 1 million elements each), and `xt`, `yt`, `zt` (also with 1 million elements each). It then populates these arrays with random values and copies the values from `x`, `y`, and `z` to `xt`, `yt`, and `zt`. Finally, it creates an array of objects (`vectors`) with three properties: `x`, `y`, and `z`.

**Individual Test Cases**

There are three test cases:

1. **SOA**: The loop iterates over the length of `x` (or `y`, or `z`) and modifies each element directly.
2. **AoS**: The loop iterates over the length of `vectors` and works on an entire object (`vector`). It copies the modified value back to the original array (`xt`, `yt`, or `zt`).
3. **SOA Mark II**: A variation of SOA that applies only to the `xt`, `yt`, and `zt` arrays, while leaving the `x`, `y`, and `z` arrays unchanged.

**Options Compared**

* SOA (Single-Assignment Optimization): Modifies each element directly in place.
* AoS (Arrays of Structures): Works on an entire structure (object) and assigns it to a temporary variable.

**Pros and Cons**

* **SOA**:
	+ Pros: Typically faster since it avoids copying values.
	+ Cons: Can lead to performance issues if the array size is large, as modifying each element individually can be slower than working on a larger data structure.
* **AoS**:
	+ Pros: Easier to implement and maintain, as it separates concerns between iteration and modification.
	+ Cons: May incur overhead from copying values.

**Library Used**

In this benchmark, there is no explicit library used. However, the use of `Float32Array` suggests that the benchmark targets modern JavaScript environments with optimized array support.

**Special JS Features/Syntax**

This benchmark does not explicitly use any special JavaScript features or syntax.

**Other Alternatives**

If you wanted to create a similar benchmark, you could consider alternative approaches, such as:

* **AoS with Caching**: Implementing caching for frequently accessed values in the `vectors` array.
* **SOA with Loop Unrolling**: Optimizing the loop iteration count and using unrolling techniques to reduce overhead.

Keep in mind that these alternatives would require significant changes to the benchmark preparation code.

Related benchmarks:

soa vs aos (version: 0)

As titled

Comparing performance of: soa vs aos vs soa mark II

Created: 9 years ago by: Guest

Jump to the latest result

soa

aos

soa mark II

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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