Specifically thinking of speed, the way to evaluate performance these days is to consider both the work done by the processor in each clock cycle and the number of clock cycles. The former is represented by the instructions per clock (IPC) and the latter is represented by frequency (in Hertz). Using this measure of performance, we can see that a 1.53 GHz Athlon processor that can execute 9 IPC is faster than a 2.0 GHz Xeon processor that executes 6 IPC.