Green Computing

This is a never ending challenge for me. Here’s my latest effort:

echo 0 > /sys/devices/system/cpu/cpu1/online
echo 15 > /proc/sys/vm/dirty_background_ratio
echo 55 > /proc/sys/vm/dirty_ratio
echo 6000 > /proc/sys/vm/dirty_writeback_centisecs
echo 9000 > /proc/sys/vm/dirty_expire_centisecs
hdparm -B 1 -S12 /dev/sda
echo 1 > /sys/module/snd_hda_intel/parameters/power_save
xbacklight -set 90
hal-disable-polling --device /dev/scd0
# to enable this again:
# hal-disable-polling --device /dev/scd0 --enable-polling
exit 0

When I try to change the link power management policy of my sata controller, it does not work. What’s up with that?

Check it out:

echo min_power > /sys/class/scsi_host/host0/link_power_management_policy && cat /sys/class/scsi_host/host0/link_power_management_policy
max_performance

It always stays min_power! ARGH! If I try something other than min_power, it throws an error, so I’m confused:

echo min_performance > /sys/class/scsi_host/host0/link_power_management_policy
bash: echo: write error: Invalid argument

Same thing happens on host1. I wonder what is up with this?

Based on some quick research, it seems like some hardware doesn’t support min_power, or that the drivers for them just aren’t set up right yet.

For what its worth, I was wondering what other options might apply here and found medium_power; that doesn’t work for me either.

The main problem I have with Google’s chromium browser is how much it writes to disk ALL THE TIME.

Seriously, is there any way to reduce Google Chome’s disk activity??

Besides Google’s chrome, I feel like my laptop is nearing cooler pastures. Right now, the fan is on all the time, and its just too hot.

I just noticed - on Ubuntu Maverick, laptop-mode-tools is not installed, it uses pm-utils and acpi-support. I just installed laptop-mode-tools, hopefully it will help!

Plug computing is really coming of age, and in my opinion - that's very cool!

What is a Plug Computer?

A plug computer is often described as a small, low-power computer that has a form factor that allows it to be plugged directly into a power outlet.

They've been around for awhile as specialty hardware. I think the first one I saw was called JackPC, and that was designed more as a computer that resembled a wall outlet than something that would get plugged into a wall outlet.

More recent plug computers look almost like power adapters, aka wall warts. The one that seems to have gathered the most attention is called the SheevaPlug. It runs on the ARM9 architecture and is marketed by Marvell and their system-on-chip called Kirkwood 6281.

Plug Computer Power Consumption

I've read that the SheevaPlug only uses 5 watts of power. If so, that would really be amazing because its reportedly quite a little powerhouse, too, in terms of processing power.

Plug Computer Uses

I'd first guess that a very useful application for a plug computer would be wireless - using the plug as a node in a wireless mesh network, or simply acting as a repeater node to extend wireless range.

After that, the sky is the limit! Prior to plug computers, enthusiasts have been modifying wireless routers with linux to act as micro-servers, even using some that have support for USB as network attached storage devices.

This brings up two important points about some plug computers:

• USB 2.0 support
• eSata support

The eSata support is really, really awesome!

Plug Computer Pricing

This is another important factor when it comes to plug computers: they are inexpensive! The SheevaPlug development kit can be purchased for only $99 USD!

Finally, REAL hybrid-energy (consumption) computer components!

Presented at this year's CES and hopefully soon to enter the marketplace, hybrid displays will be able to switch between standard LCD and e-ink. The logic being that LCD displays are better for full color imagery, and e-ink is better for e-books.

E-ink uses a lot less energy than LCD displays. As such, its the prime choice for e-book readers like the Amazon Kindle.