Poor performance

        private void glControl_Paint(object sender, PaintEventArgs e)
        {
            if (!isReady)
            {
                return;
            }
            int numQuads = 0;
            Stopwatch sw = new Stopwatch();
            sw.Start();
            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
 
            Matrix4 mLookAt = Matrix4.LookAt(eye, target, up);
 
            GL.MatrixMode(MatrixMode.Modelview);
            GL.LoadMatrix(ref mLookAt);
 
            GL.Light(LightName.Light0, LightParameter.Ambient, LightAmbient);            
 
            for (int i = 0; i < surface.Count - 1; i++)
            {
                List<Vector3> currentArch = surface[i];
                List<Vector3> nextArch = surface[i + 1];
 
                GL.BindTexture(TextureTarget.Texture2D, texSand);
                GL.Begin(BeginMode.Quads);
                GL.Color3(Color.FromArgb(255, Color.White));
                if (currentArch.Count >= 2 && currentArch.Count >= 2)
                {
                    for (int j = 0; j < currentArch.Count - 1; j++)
                    {
                        if (j < nextArch.Count - 1)
                        {
                            GL.Normal3(surfaceNormals[i][j]);
                            GL.TexCoord2(((j % 10) * 0.1f), 0 + ((j % 10) * 0.1f));
                            GL.Vertex3(currentArch[j]);
                            GL.TexCoord2(((j % 10) * 0.1f), 0.1 + ((j % 10) * 0.1f));
                            GL.Vertex3(nextArch[j]);
                            GL.TexCoord2(0.1 + ((j % 10) * 0.1f), 0.1 + ((j % 10) * 0.1f));
                            GL.Vertex3(nextArch[j + 1]);
                            GL.TexCoord2(0.1 + ((j % 10) * 0.1f), ((j % 10) * 0.1f));
                            GL.Vertex3(currentArch[j + 1]);
                            numQuads++;
                        }
                   }
                }
 
                GL.End();
            }
 
            for (int i = 0; i < dome.Count - 1; i++)
            {
                List<Vector3> currentArch = dome[i];
                List<Vector3> nextArch = dome[i + 1];
 
                if ((i % 20) == 0)
                {
                    Vector3 lightPos = new Vector3();
                    lightPos.X = currentArch[0].X + ((currentArch[currentArch.Count - 1].X - currentArch[0].X) / 2);
                    lightPos.Y = currentArch[0].Y;
                    lightPos.Z = currentArch[currentArch.Count / 2].Z - 0.5f;
                    GL.Light(LightName.Light0, LightParameter.Diffuse, LightDiffuse);
                    GL.Light(LightName.Light0, LightParameter.Position, new Vector4(lightPos, 1));
                }
 
                GL.BindTexture(TextureTarget.Texture2D, texStone);
                GL.Begin(BeginMode.Quads);
                GL.Color3(Color.FromArgb(255, Color.White));
                if (currentArch.Count >= 2 && currentArch.Count >= 2)
                {
                    for (int j = 0; j < currentArch.Count - 1; j++)
                    {
                        if (j < nextArch.Count - 1)
                        {
                            GL.Normal3(domeNormals[i][j]);
                            GL.TexCoord2(((j % 10) * 0.1f), 0 + ((j % 10) * 0.1f));
                            GL.Vertex3(currentArch[j]);
                            GL.TexCoord2(((j % 10) * 0.1f), 0.1 + ((j % 10) * 0.1f));
                            GL.Vertex3(nextArch[j]);
                            GL.TexCoord2(0.1 + ((j % 10) * 0.1f), 0.1 + ((j % 10) * 0.1f));
                            GL.Vertex3(nextArch[j + 1]);
                            GL.TexCoord2(0.1 + ((j % 10) * 0.1f), ((j % 10) * 0.1f));
                            GL.Vertex3(currentArch[j + 1]);
                            numQuads++;
                        }
                    }
                }
                GL.End();
            }