Difference between revisions of "Extending battery life on X200"
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| + | == Overview == | ||
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With the changes below and a 9 cell battery I get over 9 hours on an idle system with backlight on but at the lowest level. Before the changes I was getting a bit over 5 hours. | With the changes below and a 9 cell battery I get over 9 hours on an idle system with backlight on but at the lowest level. Before the changes I was getting a bit over 5 hours. | ||
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| + | == Details == | ||
The changes fall in 2 categories: | The changes fall in 2 categories: | ||
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** It should be noted that this does ''not'' affect performance since the clock runs at the same speeds (22700, 22600, 16000, or 800Mhz for the X200). | ** It should be noted that this does ''not'' affect performance since the clock runs at the same speeds (22700, 22600, 16000, or 800Mhz for the X200). | ||
**I used phc patches and phctools available at [[www.linux-phc.org]] for this task. | **I used phc patches and phctools available at [[www.linux-phc.org]] for this task. | ||
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| + | == Finding and removing high interrupt packages == | ||
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| + | == Reducing CPU voltage == | ||
Revision as of 20:43, 2 March 2009
Overview
With the changes below and a 9 cell battery I get over 9 hours on an idle system with backlight on but at the lowest level. Before the changes I was getting a bit over 5 hours.
Details
The changes fall in 2 categories:
- Removing packages that create unnecessarily frequent wake up interrupts.
- These interrupts wake up the CPU, preventing it from staying in its most energy efficient state.
- I used Powertop from www.lesswatts.org for this task.
- Lowering the voltage supplied to the CPU.
- Lowering the voltage supplied to the CPU has other positive side effects beside battery life: my system runs a lot cooler and ... I do not need tpfan (sw fan control for the ThinkPad), the built-in hw controller does a great job and falls back to lower speed shortly after a CPU load subsides.
- It should be noted that this does not affect performance since the clock runs at the same speeds (22700, 22600, 16000, or 800Mhz for the X200).
- I used phc patches and phctools available at www.linux-phc.org for this task.
