GCTest.cs

using System;
using System.Runtime.CompilerServices;

namespace GCTest
{
    class Program
    {
        static unsafe void Main(string[] args)
        {
            ref var refElm = ref AllocateArray();
            Console.WriteLine("0x{0:x16}", (IntPtr)Unsafe.AsPointer(ref refElm));

            ref var structElm = ref Unsafe.As<int, FooStruct>(ref refElm);
            Console.WriteLine("0x{0:x16}", (IntPtr)Unsafe.AsPointer(ref structElm));

            GC.Collect();

            Console.WriteLine("0x{0:x16}", (IntPtr)Unsafe.AsPointer(ref refElm));
            Console.WriteLine("0x{0:x16}", (IntPtr)Unsafe.AsPointer(ref structElm));
        }

        static ref int AllocateArray()
        {
            var rng = new Random();

            const int arrayCount = 100000;
            const int elementCount = 100;

            var arrays = new int[arrayCount][];

            for (var i = 0; i < arrayCount; i++)
            {
                arrays[i] = new int[elementCount];
            }

            return ref arrays[rng.Next(1, arrayCount)][rng.Next(elementCount)];
        }
    }

    struct FooStruct
    {
        public int V;
    }
}

/*
0x2633590243804
0x2633590243804
0x2633558576356
0x2633558576356
*/