EcoRenovator - groar's computers thread

I'm using computers since the age of... too young. Santa Claus brought me a Sinclair ZX81 in 1983. No color, no graphic, no sound, no key on the keyboard, only 1KB of RAM, a tape reader/recorder to load and save programs and I had to connect it to the TV in the leaving room. I quickly developed mathematical programs to verify my results to the mathematical homeworks. My friends were thinking that like in 2001: A Space Odyssey (film) I just had to talk to the computer to get my math results...

Today I have a firewall and 2 notebooks connected 24/7. These systems are PC under Gentoo Linux. My wife has her desktop, a PC under Windows. Regularly we plug our professional notebooks.

First story : why I changed my old desktop with a newer notebook.

One of my two notebooks, the one on which I'm writing this message, is in replacement of my desktop. It was a Pentium IV with 1GB RAM. It was consuming at least 80W. It was changed for several reasons :

it was too slow for what I wanted to do
it was too hot inside the "secretary" it was in
it was too noisy when we were in the same room. Problem : the secretary is in the living room.

The desktop was used to execute misc regular jobs and long run calculations, so I couldn't switch it off.

For the "too hot" problem, I used powertop : LessWatts.org - Saving Power on Intel systems with Linux.
Don't forget to read powertop's FAQ. More on powertop in a future message...
Between optimized and unoptimized configurations the processor went from 75°C to 55°C (167°F to 131°F) which did make a difference in summer in the living room temperature : 2-3°C (4-7°F).

The tests I did with the wattmeter were that the consumption were the same (remember, it was an old Pentium IV) between optimized and unoptimized. By default a processor is in "performance" mode. The default optimized configuration is the "ondemand" module which reduces the CPU frequency when idle and accelerate it when used. With the "powersave" module, the CPU frequency is always the lowest and the consumption were the same when the CPU is idle, but it was up to 25W (100W vs 125W for the whole system) when the CPU load was high.

Because the heat difference I was using the desktop in ondemand mode. For lower consumption I was killing all these graphical applications that are using much CPU and switching off the LCD when out. More about screens consumption & management in a future message...

Finally I changed that old desktop by a newer notebook, bought to my former employer when I left him, to gain in consumption. This desktop was usually over 80-100W while a notebook is usually under 30-40W... More about my notebook consumption & management in a future message...

Changing the desktop by a notebook had the effect of lower noise. When I changed my firewall 2 years ago I choose a low noise PC. More about my firewall consumption & management in a future message...

Denis.