Performance issues when loading maps in XNA / Monogame

Question

I'm new to Monogame and I'm having some perfomance issues, I'm loading a matrix of 9 maps (3x3) each with 50x50 tiles of 32x32 pixels each. I store that in a list of maps from 0 to 8 and call them by their filename from [0,0] ( [X,Y] ) up to [2,2] completing the 3x3 matrix in order to know what and where to load each new map.

Whenever my player goes to the border of the "playzone" [1,1] (the middle map) I load the respective three maps that follow, in this case I implemented the right loading, when the player heads to the right, over to [1,2] I need to load [0,3][1,3][2,3] and I unload [0,0][0,1][0,2] but whenever my game does this it stutters for a second. I might have overcomplicated things a bit and I'd love to be pointed in the right direction to optimize this. Thank you!

GameScreen class

namespace Game1.Screens
{
    public class GameplayScreen : GameScreen
    {
        Player player;
        List<Map> maps;
        float chunkWidth;
        Vector2 viewChunk;
        MapConfig mapConfig;
        XmlManager<Map> mapLoader;
        XmlManager<MapConfig> mapConfigLoader;
        bool loadingMaps;

        public GameplayScreen()
        {
            chunkWidth = 0;
            viewChunk = new Vector2(0, 0);
            mapLoader = new XmlManager<Map>();
            mapConfigLoader = new XmlManager<MapConfig>();
            mapConfig = mapConfigLoader.Load("Load/Gameplay/Maps/MapConfig.xml");
            loadingMaps = false;
        }

        public override void LoadContent()
        {
            base.LoadContent();
            XmlManager<Player> playerLoader = new XmlManager<Player>();
            player = playerLoader.Load("Load/Gameplay/Player.xml");
            player.LoadContent();
            LoadMaps(new Vector2(0,0));
            if (maps.Count > 0)
                chunkWidth = maps[0].Layer[0].TiledMap.Row.Count * maps[0].TileDimensions.X;
        }

        public void LoadMaps(Vector2 startingPosition)
        {
            maps = new List<Map>();
            int mapX = 0;
            int mapY = 0;
            int currentMapX = (int)(Math.Floor(player.CurrentPos.X / mapConfig.TileDimensions.X / mapConfig.ColumnCount));
            int currentMapY = (int)(Math.Floor(player.CurrentPos.Y / mapConfig.TileDimensions.Y / mapConfig.RowCount));
            for (int i = 0; i < mapConfig.ChunkMatrixAmount.Y; i++)
            {
                mapY = currentMapY + (i - 1);
                for (int j = 0; j < mapConfig.ChunkMatrixAmount.X; j++)
                {
                    mapX = currentMapX + (j - 1);
                    maps.Add(mapLoader.Load("Load/Gameplay/Maps/Map" + mapX + mapY + ".xml"));
                }
            }
            for (int i = 0; i <= maps.Count - 1; i++)
                maps[i].LoadContent(i, startingPosition);
            loadingMaps = false;
        }

        public override void UnloadContent()
        {
            base.UnloadContent();
            player.UnloadContent();
            foreach (Map map in maps)
                map.UnloadContent();
            maps = new List<Map>();
        }

        public override void Update(GameTime gameTime)
        {
            Vector2 endingMatrixPos = new Vector2(0, 0);
            Vector2 currentMatrixPos = new Vector2
            {   
                X = (float)(Math.Floor(player.CurrentPos.X / mapConfig.TileDimensions.X / mapConfig.ColumnCount)),
                Y = (float)(Math.Floor(player.CurrentPos.Y / mapConfig.TileDimensions.Y / mapConfig.RowCount))
            };

            //Load a new RIGHT and unload LEFT
            if (currentMatrixPos.X >= Math.Floor(maps[5].Layer[0].Image.Position.X / mapConfig.TileDimensions.X / mapConfig.ColumnCount) &&
                maps[8].Layer[0].Image.Position.X != 0 && 
                !loadingMaps)
            {
                loadingMaps = true;
                foreach (Map map in maps)
                    map.UnloadContent();
                endingMatrixPos.X = maps[0].Layer[0].Image.Position.X + mapConfig.TileDimensions.X;
                endingMatrixPos.Y = (maps[0].Layer[0].Image.Position.Y + mapConfig.TileDimensions.Y) - (mapConfig.TileDimensions.Y * mapConfig.RowCount);
                LoadMaps(endingMatrixPos);
            }

            base.Update(gameTime);
            player.Update(gameTime);
            foreach (Map map in maps)
                map.Update(gameTime, ref player);
            if (player.CameraFollow)
            {
                Camera.IsFollowingObject = true;
                Camera.Pos = -player.CurrentPos;
            }
            Camera.Update();
        }

        public override void Draw(SpriteBatch spriteBatch)
        {
            spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, SamplerState.PointClamp, null, null, null, Camera.Transform);
            base.Draw(spriteBatch);
            foreach (Map map in maps)
                map.Draw(spriteBatch, "Underlay");
            player.Draw(spriteBatch);
            foreach (Map map in maps)
                map.Draw(spriteBatch, "Overlay");
            spriteBatch.End();
        }
    }
}

If you need more information I'll provide it when possible! Thank you for your help again!

Answer 1

First, don't load every file in every time. If you load in a 3x3 square when you leave the center square, then you'll throw away 6 or 4 tilemaps based on the player's direction. That's a huge waste.

Second, 3x3 is very small. In fact, if your map isn't literally thousands of tiles in each direction, then the Memory should be able to handle it. Yes, memory is expensive, but if a 2011 PC could handle a big chunk of Skyrim's world at once, then it should be able to work with a tiled map.For example, my MonoGame project could load in 10,000 different tiled maps in a very inefficient format, each having 32 x 32 tiles without even remotely maxing out my 4GBs of memory (that's 10,240,000 integer if you're curious, which is around 40,960,000 bytes or around 39 MB). Just apply some sort of culling so only the visible maps are drawn.

And last, if you need to do any kind of IO do it in a separate thread. There's no reason to make the player wait for