https://shibuya24.info/entry/unity-getcomponent サンプルコード

ComponentPerformanceTest.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Profiling;

public enum TransformAccessType
{
    transformAccess,
    GetComponentAccess,
    CachedTransform,
}

public class ComponentPerformanceTest : MonoBehaviour
{
    // インスペクタから切り替えて負荷確認
    public TransformAccessType type;
    Transform t;

    void Update ()
    {
        if (t == null)
        {
            t = transform;
        }
        Profiler.BeginSample ("### Check Transform ###");
        for (int i = 0; i < 10000; i++) {
            if (type == TransformAccessType.CachedTransform)
            {
                // Transformをキャッシュして使用
                t.localPosition = Vector3.zero;
            }
            else if (type == TransformAccessType.GetComponentAccess)
            {
                // GetComponentを使用
                GetComponent<Transform> ().localPosition = Vector3.zero;
            }
            else
            {
                // transformアクセス
                transform.localPosition = Vector3.zero;
            }
        }
        Profiler.EndSample ();
    }
}