>> Yes, you are right. On a mobile device you want to avoid random >> accesses to the data structure, because RAM is scarce and I/O is >> pretty expensive. The good news is that it is perfectly possible to >> rearrange the data structures in a way that only a handful of I/Os >> are necessary to compute a route. > > You would you avoid random IO?
Let me make that more clear. The problem is the number, no the locations of the I/Os. A good arrangement of the data gives also good cache-effects. > On a flash-chip random IO is as cheap as > linear IO and not much slower then RAM > access. (both chips being on the same > memory-bus and no caching or speculative > reading in an ARM CPU) Accessing flash linearily gives good cache effects and flash is certainly not as fast as RAM. --Dennis _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing
