Seeing that the GVP ram is so expensive my 040 combo has 16mb fully populated, so the extra 6mb from the HC+8 (can't use its 8mb because of the picasso ii 2mb) is nice boost.
Actually, it won't give any boost at all, it may actually slow things down. Memory-access to the RAM on the HC+8 will be way slower than to the RAM on the 040-board, so programs will actually run slower if they get loaded to, or use data on, that 6MB area.