You talk about the GT 730 as if it was ONE card. In fact you have 3 TOTALLY DIFFERENT models under the same name. There is no comparison for example between a GT 730 with 12GB/sec memory bandwidth and one with 40GB/sec memory bandwidth. Rebrands. For the 520 it says 1st Gen GPU, so possibly a 7730, and for 530 it says 3rd Gen, so possibly a 240/250 rebrand.