> I'm getting around 75% in C4, the rest almost exclusively in C0. This 25% in C0 is likely all of your battery life problem. use top and powertop to find out what is running and why, and see if it is something you can prevent from running. If your CPU is more than 1% buys when "profoundly idle", then it has a significant software or configuration problem. cheers, Len Brown, Intel Open Source Technology Center ps. note for comparisons... your XP partition should have a "perfmon" application that can draw a pretty graph of cpu usage, including adding counters for the various C-states. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html