1. A method of determining device characteristics, comprising: obtaining a first globally accessible value; if the first globally accessible value corresponds to a stored first value, obtaining device characteristics data from a relatively fast memory; if the first globally accessible value does not correspond to the stored first value, obtaining a second globally accessible value; if the second globally accessible value corresponds to a stored second value, obtaining device characteristics data from a relatively fast memory; if the second globally accessible value does not correspond to the stored second value, obtaining device characteristics data from a relatively slow memory and updating the relatively fast memory, the stored first value, and the stored second value.