These changes speed up how long it takes to populate the GameGrid after clicking on a dat in the Tree. MAME 0.155 dat was used for testing. Before the changes population times were windows .net = 2.75 seconds linux mono = 23 seconds After the changes, both now take 300-400ms. This was done using 2 main changes. 1. Fully move populating the rows' Values to the CellFormatting function 2. Determine the total number of rows we will need and use GameGrid.rowCount to set the row count to that. This is much faster then doing individual Add()'s for each row.