Thinkpad T510: LAN? CPU-C3?

[Jan Henrik Sylvester]

On 03/30/2010 08:50, Alexander Motin wrote:
> Jan Henrik Sylvester wrote:
>> - CPU-C3: No C3 (dev.cpu.0.cx_supported: C1/3 C2/245) for i7-620M.
>> Battery life will not be good without C3, and Turbo Boost will not work
>> either. (Apparently, Linux got C3 support on a quick boot with a live CD.)
>
> I would say that your C2 state has too high entering latency (at least
> from point of my C2D of C1/1 C2/1 C3/57). May be you have some C2E hack
> enabled in BIOS, which makes C3 useless and BIOS hides it? FreeBSD
> receives all info about supported states from ACPI BIOS, so ACPI can
> report whatever it wants about set of C-states.

Thanks for the hint. 245 is indeed very high for C2. I did boot up Linux 
(2.6.28.4) to check what it is saying.

/proc/acpi/processor/CPU[0123]/power:
active state: C0 max_cstate: C8 bus
master activity: 00000000 maximum allowed latency: 16000 usec
C1: type[C1] promotion[--] demotion[--] latency[003]
C2: not supported
C3: type[C1] promotion[--] demotion[--] latency[245]
C1 usage CPU0:12462 CPU1:11900 CPU2:10055 CPU3:06025
C3 usage CPU0:53886 CPU1:52762 CPU2:52434 CPU3:53555

I guess what FreeBSD reports as C2 is in fact C3.

With the P-/C-states optimizations from the Wiki, I have 85%--95% C2 
utilization for an idle xorg+KDE4.

I do not think it is about BIOS settings (I pasted them below) but about 
FreeBSD that cannot deal with C2 missing, but C1 and C3 available. Or?

Thanks you all for your help!
Jan Henrik



#Power#
Timer Wake with Battery Operation: Disabled (Enabled)
Intel(R) SpeedStep technology: Enabled (Disabled)
- Mode for AC: Maximum Battery (Maximum Performance, Battery Optimized, 
Automatic*)
- Mode for Battery: Maximum Battery (Maximum Performance, Battery 
Optimized*, Automatic)
Adaptive Thermal Management
- Scheme for AC: Balanced (Maximize Performance*)
- Scheme for Battery: Balanced (Maximize Performance)
CDROM Speed: Normal (High, Silent)
CPU Power Management: Automatic (Disable)
PCI Bus Power Management: Automatic (Disable)
PCI Express Power Management: Automatic (Disable)
#CPU#
Core Multi-Processing: Enabled (Disabled)
Intel(R) Hyper-Threading Technology: Enabled (Disabled)
Intel(R) Virtualization Technology: Disabled (Enabled)
Intel(R) VT-d Feature: Disabled (Enabled)