Yeah, you need to configure it to tell it what configuration of cache you want to simulate (there's an example of doing this for the Jaguar cache in slides 84/8

Yeah, you need to configure it to tell it what configuration of cache you want to simulate (there's an example of doing this for the Jaguar cache in slides 84/85). Valgrind's cachegrind tool also lets you tweak the cache config it simulates. Some bugs are going to cause problems regardless of the cache config (like the "access a cold page unnecessarily every iteration of the loop" examples); some might be more sensitive to exact cache configuration.