Thinkpads Forum

I recently got a Kill-A-Watt meter, and I thought I'd do some power usage tests on my T400.

All these tests are run with Windows 7 Ultimate x64 SP1, most background programs killed for minimal CPU usage. All wireless radios are turned on. Although my ThinkPad has switchable graphics I have the only use discrete graphics option selected for now.

Minimum Brightness + Idling: 22-25 watts
Maximum Brightness + Idling: 26-28 watts

Then I tried to load it as much as possible with a specialized software to burn in the CPU and GPU at the same time.

Maximum Brightness + Full load on CPU and GPU: 72-75 watts

The maximum load of my power brick is 90 watts so it seems to be well within range. Thinking of doing the same tests on my old X41T for fun if anyone wonders.

Here is also a graph showing it's specs and the temps during the test.



It doesn't really get hot when idling nor when running a regular burn in test, but good grief it sure does get hot when burning the CPU AND GPU at the same time!

Good day.

Perhaps this information may someday be useful to someone.
~Re

this is actually pretty cool

ReCreate wrote:Maximum Brightness + Full load on CPU and GPU: 72-75 watts

Note that those readings are measuring power into the power supply, not power used by the laptop, i.e., even if the power supply were 85% efficient -- which it probably is not -- the power consumed by the laptop would be less than 60 Watts max. Most likely, the maximum used by the laptop is circa 50 Watts.