GC collects ... what?

Question

I am trying to optimize my engine (C # + SlimDX) to make as few distributions as possible (to prevent GC from turning on too often), using the profiler as a reference, which gives me where the garbage object is generated. Its movement is pretty good (with 20 MB it is reset every 5 with 8 MB, every month and a half (yes, it was very little optimized by XD)) There is a method where I cannot find anything declared and I don’t know what to do . It seems that this method generates 2 objects with garbage to execute in their body (not on the called function):

Can someone help me understand why this function generates an object for garbage? I really have no clue.

    public override void Update()
    {
        base.Update();
        if (LastCheckInstancesNumber != Instances.Count)
        {
            LastCheckInstancesNumber = Instances.Count;
            _needToRegenerateUpdate = true;
        }
        // Crea byte array da usare nel prossimo draw.
        if (_needToRegenerateUpdate)
        {
            Int32 PrimitivesCount = Instances.Count;
            Int32 Size = PrimitivesCount * 80;

            if ((ByteUpdateTemp != null) && (ByteUpdateTemp.Length < Size))
                ByteUpdateTemp = new byte[Size];
            int offset = 0;

            PrimitivesCount = 0;
            Int32 Count = Instances.Count;
            for (int i = 0; i < Count; i++)
            {
                InstancedBase3DObjectInstanceValues ib = Instances[i];
                if (ib.Process)
                {
                    MathHelper.CopyMatrix(ref ib._matrix, ref MatrixTemp);
                    MathHelper.CopyVector(ref ib._diffuseColor, ref ColorTemp);

                    ObjectUpdateTemp[0] = MatrixTemp.M11;
                    ObjectUpdateTemp[1] = MatrixTemp.M12;
                    ObjectUpdateTemp[2] = MatrixTemp.M13;
                    ObjectUpdateTemp[3] = MatrixTemp.M14;
                    ObjectUpdateTemp[4] = MatrixTemp.M21;
                    ObjectUpdateTemp[5] = MatrixTemp.M22;
                    ObjectUpdateTemp[6] = MatrixTemp.M23;
                    ObjectUpdateTemp[7] = MatrixTemp.M24;
                    ObjectUpdateTemp[8] = MatrixTemp.M31;
                    ObjectUpdateTemp[9] = MatrixTemp.M32;
                    ObjectUpdateTemp[10] = MatrixTemp.M33;
                    ObjectUpdateTemp[11] = MatrixTemp.M34;
                    ObjectUpdateTemp[12] = MatrixTemp.M41;
                    ObjectUpdateTemp[13] = MatrixTemp.M42;
                    ObjectUpdateTemp[14] = MatrixTemp.M43;
                    ObjectUpdateTemp[15] = MatrixTemp.M44;
                    ObjectUpdateTemp[16] = ColorTemp.X;
                    ObjectUpdateTemp[17] = ColorTemp.Y;
                    ObjectUpdateTemp[18] = ColorTemp.Z;
                    ObjectUpdateTemp[19] = ColorTemp.W;
                    ByteConverter.WriteSingleArrayToByte(ref ObjectUpdateTemp, ref ByteUpdateTemp, offset);
                    offset += 20;

                    PrimitivesCount++;
                }
            }

            SynchronizedObject so = SynchronizationEventWriter.LockData();
            so.Synchronizedobject = ByteUpdateTemp;
            SynchronizationEventWriter.Update();
            SynchronizationEventWriter.UnlockData();
            _needToRegenerateUpdate = false;

            so = SynchronizationEventWriterNum.LockData();
            so.Synchronizedobject = PrimitivesCount;
            SynchronizationEventWriterNum.Update();
            SynchronizationEventWriterNum.UnlockData();
        }
  }

Notes:

[] - . MathHelper (Single) -. .Update() ( , )

!!!

EDIT:

    internal void GetLock()
    {
        Monitor.Enter(InternalLock);
        Value.Locked = true;
        Value.LockOwner = Thread.CurrentThread;
    }
    public SynchronizedObject LockData()
    {
        Parent.GetLock();
        return Parent.Value;
    }

LockData(). , - : |

Answer 1

!!!

, so.Synchronizedobject = PrimitivesCount; Int32 Object. , , . , , Int32 .

Answer 2

base.Update(), -?

? , , . , .

, () .

MathHelper ?

Answer 3

, , SynchronizedObject :

SynchronizedObject so = SynchronizationEventWriter.LockData();

so = SynchronizationEventWriterNum.LockData();

SynchronizedObject LockData() -, , ...