Hi, I was trying to chase down a theory that my desktop machine (a core i7) is running warm (the fan sounds like it's at full speed all the time, and I think it's not always acted this way -- hence the theory). powertop is never showing it spending any time in C3... I compiled a kernel without USB/sound/radeon, and ran without X. I was able to get the wakeups/sec down below 20, but no time is spent in C3. sysfs looks to agree with powertop here (time = 0 on C3): /sys/devices/system/cpu/cpu0/cpuidle/state0/desc: CPUIDLE CORE POLL IDLE /sys/devices/system/cpu/cpu0/cpuidle/state0/latency: 0 /sys/devices/system/cpu/cpu0/cpuidle/state0/name: C0 /sys/devices/system/cpu/cpu0/cpuidle/state0/power: 4294967295 /sys/devices/system/cpu/cpu0/cpuidle/state0/time: 457 /sys/devices/system/cpu/cpu0/cpuidle/state0/usage: 59 /sys/devices/system/cpu/cpu0/cpuidle/state1/desc: ACPI FFH INTEL MWAIT 0x0 /sys/devices/system/cpu/cpu0/cpuidle/state1/latency: 1 /sys/devices/system/cpu/cpu0/cpuidle/state1/name: C1 /sys/devices/system/cpu/cpu0/cpuidle/state1/power: 1000 /sys/devices/system/cpu/cpu0/cpuidle/state1/time: 308177 /sys/devices/system/cpu/cpu0/cpuidle/state1/usage: 3975 /sys/devices/system/cpu/cpu0/cpuidle/state2/desc: ACPI FFH INTEL MWAIT 0x10 /sys/devices/system/cpu/cpu0/cpuidle/state2/latency: 17 /sys/devices/system/cpu/cpu0/cpuidle/state2/name: C2 /sys/devices/system/cpu/cpu0/cpuidle/state2/power: 500 /sys/devices/system/cpu/cpu0/cpuidle/state2/time: 873440787 /sys/devices/system/cpu/cpu0/cpuidle/state2/usage: 239038 /sys/devices/system/cpu/cpu0/cpuidle/state3/desc: ACPI FFH INTEL MWAIT 0x20 /sys/devices/system/cpu/cpu0/cpuidle/state3/latency: 17 /sys/devices/system/cpu/cpu0/cpuidle/state3/name: C3 /sys/devices/system/cpu/cpu0/cpuidle/state3/power: 350 /sys/devices/system/cpu/cpu0/cpuidle/state3/time: 0 /sys/devices/system/cpu/cpu0/cpuidle/state3/usage: 0 This may be a complete red herring, but I added some printk logic to acpi_idle_bm_check(), and it is getting called often, but bm_status is always 1. [I infer from this that the idle logic is trying to go into C3, but this check is stopping it... Unless I misread something.] Is this expected behavior or is this a legitimate problem? How might I investigate this further? Attaching dmesg, /proc/cpuinfo, powertop -d output. Thanks, Jeff Garrett