Donald builds a 1 GHz processor where two important programs, A and B, take one second each to execute. Each program has a CPI of 1. Elaine is tasked with designing the company's next-generation processor. She comes up with an idea that improves the CPI of A to 0.8 and the CPI of B to 0.6. But the idea is so complex that she is struggling to support the same clock speed as before. What is the minimum clock speed she needs to support so that the new processor performs better than the old processor?