When powered by AC the system performance is excellent. When powered by battery, the system is so sluggish that I prefer to just not use it. It is like it was running at 200 MHz.
This occurs with frequency scaling turned OFF and the CPU running at 1788MHz. Is this the result of on-chip powersaving systems of the CPU, such as the delay time for the chip to go from low-power mode to full power? Is there any way of tweaking this behavior?
Note the differences in the results of the bogomips benchmark below.
Thanks, Erik
Relvant lines from kernel messages:
CPU#0: Initializing PID hash table entries: 4096 (order 12: 32768 bytes) Detected 1788.655 MHz processor. CPU#0: Calibrating delay loop... 3538.94 BogoMIPS CPU#0: After generic identify, caps: 0383f9ff c1cbf9ff 00000000 00000000 CPU#0: After vendor identify, caps: 0383f9ff c1cbf9ff 00000000 00000000 CPU#0: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line) CPU#0: L2 Cache: 512K (64 bytes/line) CPU#0: After all inits, caps: 0383f9ff c1cbf9ff 00000000 00000020 CPU#0: Intel machine check architecture supported. CPU#0: Intel machine check reporting enabled. CPU: AMD mobile AMD Athlon(tm) XP2400+ stepping 00 CPU#0: Enabling fast FPU save and restore... done. CPU#0: Enabling unmasked SIMD FPU exception support... done. CPU#0: Checking 'hlt' instruction... OK. CPU#0: Machine check exception polling timer started. powernow: PowerNOW! Technology present. Can scale: frequency and voltage. powernow: Found PSB header at c00f15c0 powernow: Table version: 0x12 powernow: Flags: 0x0 (Mobile voltage regulator) powernow: Settling Time: 100 microseconds. powernow: Has 14 PST tables. (Only dumping ones relevant to this CPU). powernow: PST:12 (@c00f16ac) powernow: cpuid: 0x781 fsb: 133 maxFID: 0x15 startvid: 0xb powernow: FID: 0x12 (4.0x [532MHz]) VID: 0x13 (1.200V) powernow: FID: 0x4 (5.0x [665MHz]) VID: 0x13 (1.200V) powernow: FID: 0x6 (6.0x [798MHz]) VID: 0x13 (1.200V) powernow: FID: 0x8 (7.0x [931MHz]) VID: 0x13 (1.200V) powernow: FID: 0xe (10.0x [1330MHz]) VID: 0xe (1.300V) powernow: FID: 0x15 (13.5x [1795MHz]) VID: 0xb (1.450V)
powernow: Minimum speed 532 MHz. Maximum speed 1795 MHz.
(Note, I have a patch applied to my kernel to set the cpuid to 0x781 so that the powernow scaling driver works. The original cpuid is 0x7a0)
On AC power: ============ ============
nx9:~# bogomips Calibrating delay loop.. ok - 1760.00 BogoMips
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq: 1795500 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq: 532000 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies: 532000 665000 798000 931000 1330000 1795500: :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors: powersave userspace performance :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver: powernow-k7 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: performance :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq: 1795500 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq: 532000
/proc/cpuinfo:
processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 10
model name : mobile AMD Athlon(tm) XP2400+
stepping : 0
cpu MHz : 1788.828
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow
bogomips : 3538.94
nx9:/proc/acpi/processor/CPU0# more *
::::::::::::::
info
::::::::::::::
processor id: 0
acpi id: 0
bus mastering control: yes
power management: yes
throttling control: no
limit interface: no
::::::::::::::
limit
::::::::::::::
<not supported>
::::::::::::::
power
::::::::::::::
active state: C2
default state: C1
bus master activity: 00000000
states:
C1: promotion[C2] demotion[--] latency[000] usage[00029760]
*C2: promotion[--] demotion[C1] latency[100] usage[00418342]
C3: <not supported>
::::::::::::::
throttling
::::::::::::::
<not supported>
On battery power: ================ ================
nx9:~# bogomips Calibrating delay loop.. ok - 612.00 BogoMips
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq: 1795500 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq: 532000 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies: 532000 665000 798000 931000 1330000 1795500 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors: powersave userspace performance :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver: powernow-k7 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: performance :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq: 1795500 :::::::::::::: /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq: 532000
cat /proc/cpuinfo:
processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 10
model name : mobile AMD Athlon(tm) XP2400+
stepping : 0
cpu MHz : 1788.828
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow
bogomips : 3538.94
nx9:/proc/acpi/processor/CPU0# more *
::::::::::::::
info
::::::::::::::
processor id: 0
acpi id: 0
bus mastering control: yes
power management: yes
throttling control: no
limit interface: no
::::::::::::::
limit
::::::::::::::
<not supported>
::::::::::::::
power
::::::::::::::
active state: C2
default state: C1
bus master activity: 00000000
states:
C1: promotion[C2] demotion[--] latency[000] usage[00028280]
*C2: promotion[--] demotion[C1] latency[100] usage[00379537]
C3: <not supported>
::::::::::::::
throttling
::::::::::::::
<not supported>
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