GSO means that the new version of this model of graphics card is newer than GT, but its performance is not as good as GT on monitors over 20 inches, and its memory is not as big as GT's, as is TC5 12 ***. Enjoy 5 12 megabytes of video memory. Without video memory, graphics cards will naturally compete with system memory for resources. GD3 means that memory granules are colorful and famous for DDR3 generation. Graphics cards are not outstanding. Be careful when buying graphics cards. Never buy quality cards.