Don't know if we can call this rumors, the comparison is close to reality, anyways according to the leaked results from It168.com, the mid-range Nvidia's 600 series, Geforce GTS 650 graphic card will perform faster than GTX 550 Ti and GTS 450, this will be the direct rival to the AMD's Radeon HD 7770.
GeForce GTS 650
The benchmark result is done using 3DMark 2011 and 3DMark vantage at performance preset comparing the GTS 650 with the GTX 550 Ti, GT 640 and GTS 450, and the new generation take the lead, the Geforce GTS 650 will use the Kepler GK107 GPU which pack 384 CUDA cores, same as the GT 640, but the GTS 650 will be clocked at a higher frequency, may be a 1000Mhz is enough for these scores, I can guaranty a 1200Mhz after a good overclocking, also the GDDR5 lock will be more than 4700Mhz effective clock, the price will be at the range 115$ to 125$ as the GT 640 is as low as 95$, if you are planing to upgrade to the GT 640, I advise to wait, add some $, buy a GTS 650 and you'll get an optimal performance for every dollar you pay.
GeForce GTS 650 Benchmark
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