Well, the performance should be quite similar (although not exactly sure), but the 1050Ti uses maximum about 75 Watts of power while the 7970 (especially the GHz edition) I believe can use 200+ Watts under full load. That's the main difference I guess, it's pretty much new vs. old technology. Also it's 4GB memory vs. 3GB on the 7970, so the 1050Ti is a bit more futureproof there.