C-states on core-i7m

[John Baldwin]

On Sunday 18 April 2010 4:52:33 am Andreas Nilsson wrote:
> 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?

I have used C3 on i7 CPUs.  I would check your BIOS options perhaps.  Note 
that in the BIOS what shows up as "C3" to ACPI may be called "C6/C7".

-- 
John Baldwin