Friday, 29 October 2004

Filtering Active GPO settings

I found out that the Microsoft Group Policy Editor can be configured to show only group policy settings that have actual settings in them rather than a mass of "configured".

You can only do this for Administrative Templates but just right click on the right hand side and select this option.

Stuck in Dublin

I've just remembered why I hate flying so much.  Well, not the flying, the boring "stuck in airport" bit.  I was a tad over optimistic with the material I could fill a 3 day "workshop" course for so ended up finishing an hour and a half early.  The meant I got to Dublin airport at 16:30 for a 20:00 flight only to find it was delayed till 21:00.

Sigh.

Tuesday, 12 October 2004

Windows Disk Repair Tool

Had a bit of disaster at work - Volume (not backed up) decided to lose it's volume information.  Found a reasonably priced disk recovery tool:

R-Studio NTFS

It's a little slow (we're talking about a 250GB volume mind you) but quite competitively priced at $49.99.  You can find a demo here.  It handles FAT, NTFS (Basic and Dynamic volumes) and Ext2FS (Linux).

Monday, 11 October 2004

Sunday, 3 October 2004

ACPI Throttling on Inspiron 5100

As the Dell Insprion 5100 has a standard desktop P4 processor it doesn't support power management but I am experimenting with ACPI throttling to extend battery power life/reduce temperature.  Here's the output from x86info:

wendy:~ # x86info
x86info v1.10.  Dave Jones 2001, 2002
Feedback to <davej@suse.de>.
Found 1 CPU
Family: 15 Model: 2 Stepping: 7 Type: 0 [Pentium 4 (Northwood) [C1] Original OEM]
Processor name string:               Intel(R) Pentium(R) 4 CPU 2.66GHz


You can prove this yourself by the following:

wendy:~ # cat /proc/acpi/processor/CPU0/info
processor id:            0
acpi id:                 0
bus mastering control:   yes
power management:        no
throttling control:      yes
limit interface:         yes

You notice the power management: no in the above output No CPU power management Im afraid.  This is further proven because the performance file is missing:

wendy:~ # cat /proc/acpi/processor/CPU0/performance
cat: /proc/acpi/processor/CPU0/performance: No such file or directory

Also there is only one powerstate supported in the power file:

wendy:~ # cat /proc/acpi/processor/CPU0/power
active state:            C1
default state:           C1
bus master activity:     00000000
states:
   *C1:                  promotion[--] demotion[--] latency[000] usage[00000000]
    C2:                 
    C3:                 

However, going back to the output from /proc/acpi/processor/CPU0/info youll notice that throttling is supported.  This is also proven by the output of /proc/acpi/processor/CPU0/throttling:

wendy:~ # cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
states:
   *T0:                  00%
    T1:                  12%
    T2:                  25%
    T3:                  37%
    T4:                  50%
    T5:                  62%
    T6:                  75%
    T7:                  87%

Notice the * before T0.  This indicates that there is 00% throttle on the processor, i.e. its running at 100%.  If we change this to anything between T1-T7 we can reduce the processor from running quite so fast:

T0         100%    2.66GHz
T1         88%      2.34GHz
T2         75%      2GHz
T3         63%      1.68GHz
T4         50%      1.33GHz
T5         38%      1.01GHz
T6         25%      665MHz
T7         13%      346MHz

Ive tested this by running xscreensaver and observing a visible slowdown.  I have not done any testing on thermal or battery effects Let me know if you do!

wendy:~ # cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
states:
   *T0:                  00%
    T1:                  12%
    T2:                  25%
    T3:                  37%
    T4:                  50%
    T5:                  62%
    T6:                  75%
    T7:                  87%
wendy:~ # echo -n 4 > /proc/acpi/processor/CPU0/throttling
wendy:~ # cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T4
states:
    T0:                  00%
    T1:                  12%
    T2:                  25%
    T3:                  37%
   *T4:                  50%
    T5:                  62%
    T6:                  75%
    T7:                  87%

Here's a good website that describes the ACPI interface:
http://acpi.sourceforge.net/documentation/processor.html