The second generation Intel Core i5-2520M processor features Turbo Mode 2.0 technology. That means that the clock speeds vary depending on what the load is on the processor.
Each Intel processor has different clock speeds in turbo mode, so take a look at the chart above to see what some of the most popular mobile processor speeds are. As you can see from the chart the Intel Core i5-2520M in our ASUS K53E notebook has a 2.50GHz base frequency, but can go all the way up to 3.2GHz in single core operation and 3.0GHz in dual-core use.
With the ASUS K53E notebook at an idle the Intel Core i5-2520M ran at 800MHz with 0% load on all of the cores. By clock-gating the mobile processor and lower the voltages running the processor at 800MHz this low power state helps extend the battery life of your notebook. The second you demand more processing power the clock speed increases to a pre-programmed level depending on how many cores you are using.
When running an application that uses one physical core you’ll see the Intel Core i5-2520M processor running at a clock frequency of 3.2GHz! This is 700MHz over it’s rated speed of 2.5GHz and Turbo Mode 2.0 basically overclocks the processor for you on the fly. The frequency range of the Intel Core i5-2520M processor is 800MHz to 3200MHz.
With all both the cores and hyper-threads running at full load we saw the processor running at 2.9GHz, this is lower than single core use as Intel must keep the thermal envelope of the processor within specifications so the notebook manufactures know exactly what the peak temperatures will be. What’s odd with these new ‘Sandy Bridge’ mobile processors is that you seldom see them running at their base clock frequency. For example we never saw 2.5GHz when taking the screen shots!