Toshiba A135-S4427 consumes 20 Watts

Yes, that's what my Watts-Up reads - tapped between the 120v AC power supply and the laptop - w/battery removed.

Because I live off-grid, I was pondering the purchase of a more efficient laptop/netbook. But now, I'm not seeing much, if any, advantage in spending the $. My first choice would've been an Asus UL30A/UL30VT, after reading Notebookcheck's review. NC reports 4.4 / 7.6 / 8.8 Watts at idle, and 21.7 / 28.5 watts loaded. My A135 uses 19.7 / 20.5 watts average (it doesn't appear to make much difference loaded (web surfing & 80% screen brightness) or idle. I even DL'ed a HD scrubber prg just to load the hard drive and the wattage increased slightly to about 21.5. However, when I initiate standby, it drops to about .05w.

My Toshiba A135-S4427
Intel T2250 cpu
2gb memory
WD Black 7200 HD
Alfa AWUS051NH USB wifi adapter.

 

I'm not sure what you were expecting, but I must say that a constant 20W seems pretty decent I suppose.

My current notebook (14" screen, previous generation Core 2 Duo - according to the battery meter and not taking account inefficiency of the AC adapter) seems to consume about 10-16W in idle.

The only reason reason I think you would want a new notebook computer is if you want something faster, if there is anything that your current computer can't do for you.

 

Exactly...

 

I was expecting closer to double - 40-50w.

The Asus UL30 has the 1.3Ghz SU7300 CPU rated at 10w TDP and a 13" LED screen. My A135 is a 1.7Ghz T2250 CPU rated at 31w TDP with a 15" display. I'm not into videos and don't need any more processing speed, but the thought of moving to a squinted, 16:9 x 13" display would be difficult to accept with my aging eyes. So needless to say, I'm not complaining. However, I am curious how NC arrived at their numbers.

 

They don't use a power meter, or whatever it is you are using (they use software on the computer itself -when the computer is running on battery power the software uses data like battery capacity, rate of battery drain, ect... which comes out with a pretty accurate figure for how much energy the laptop itself uses)

When you measure the draw the laptop power supply has [even if it is off the power jack like it looks like it is]... well of course it will be quite a bit greater than what the laptop itself is using internally (first, they aren't designed to 'know' when the laptop is idling and only supply a tiny amount of power, then 'know' when you are doing demanding things... they just pump out power 24/7 as long as they are plugged in and having power drawn -though a greater load will result in a even greater strain on the power brick, making it heat up), Electronics [especially power supplies] are also very inefficient things -even the 'power converters' in the laptop itself-, and you can't overcome that
You can use the free version of 'battery bar' to see how many watts your computer draws when on battery power -its the same value for when plugged in- so you know the draw of the computer itself


and you absolutely cannot trust TDP to tell you which processor will be more efficient (they tend to lie a lot... or rather no tell you how they run normally)- though the SU7300 is actually is a pretty efficient processor

 

In BOTH examples (NC's review and my tests), the power 'source' is irrelevant. Can be batteries, the AC power supply or even a solar module. What is being measure here, is notebook consumption and it's peripheral - nothing more, nothing less.