C-states on core-i7m

Andreas Nilsson andrnils at gmail.com
Sun Apr 18 09:21:40 UTC 2010


Hello,

my new laptop has a core-i7 620m and I expected it to have support for
C3-state.
sysctl dev.cpu.0
dev.cpu.0.%desc: ACPI CPU
dev.cpu.0.%driver: cpu
dev.cpu.0.%location: handle=\_PR_.CPU0
dev.cpu.0.%pnpinfo: _HID=none _UID=0
dev.cpu.0.%parent: acpi0
dev.cpu.0.freq: 149
dev.cpu.0.freq_levels: 2667/25000 2533/23710 2399/22465 2266/21243
2133/20027 1999/18852 1866/17700 1733/16571 1599/15478 1466/14395 1333/13334
1199/12297 1049/10759 899/9222 749/7685 599/6148 449/4611 299/3074 149/1537
dev.cpu.0.cx_supported: C1/3 C2/245
dev.cpu.0.cx_lowest: C2
dev.cpu.0.cx_usage: 100.00% 0.00% last 500us

I've never seen it acutally use even C2. Are lower C-states not supported
yet for the core i7 cpus?

Regards
andrnils


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