Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

It's really confusing. When plugged in, everything is lagging. On battery everything goes smooth, three times as fast.

I looked into power options, set everything to default and tried the three modes: power saver, balanced and performance.

What could be the problem?


  • Dell Inspiron N7110

  • Intel(R) Core(TM) i7-2670QM CPU @ 2.2GHz (8CPUs) / 8 GB RAM

  • Windows 8 Pro 64-bits

EDIT 1: After a little investigation, I noticed that the needed energy for my laptop is 130W and my charger only provides 90W. I don't think this is where the issue is because the problem did not arise when I bought this charger but way later.

Is there a way to better manage my power settings? Or at least some way to use both the charger and battery at the same time and decrease battery consumption.

EDIT 2: It seems my problem arises if I unplug the power cord and put it back.

share|improve this question
Is there more than 1 power management software installed? Or any settings in the BIOS for this? – Dave Sep 12 '13 at 11:27
No, I didn't install any power management software. As for BIOS settings, I didn't change anything. – Wajih Aziza Sep 12 '13 at 11:37
I meant did any come pre-installed. In regards to BIOS settings, you said you didn't change anything which indicates this is a new issue? – Dave Sep 12 '13 at 11:49
It is new, also I installed windows 8 and the drivers myself. – Wajih Aziza Sep 12 '13 at 14:38
Please check out… – Dave Sep 12 '13 at 14:52

I would suspect the battery or charger is faulty. However, before buying a new one, the quote below is for XP and I don't offer it as a result, more of a place to start looking.

I noticed in PROCESS EXPLORER that, whenever i plug the power, it was only one occurrence of SERVICES.EXE to produce a big overload to CPU. This occurrenc of SERVICE.EXE is the one that supports PLUG&PLAY SERVICES and EVENT SERVICES. I started to focus the problem in another way: when my laptop works with batteries, XP throttle some process in order to lower power consumption and this hides the real problem. So I focused on this: what is throttled working in battery mode and consumes CPU in power plug mode?

The answer was quite simple: SERVICE.EXE was yet addressed, I excluded PLUG&PLAY and focused on EVENT SERVICES. I made a tour on EVENT VIEWER and it was simple to discover that SECURITY EVENT LOG had exceded the limits (it was set up for a maximum size of 512kB, but the real size was 80MB!!!). It was quite simple to clear the log in order to gain full CPU avalability (obviously I made a back up of the log).


share|improve this answer
CPU usage remains 12% whether plugged in or on battery. And I didn't notice any changes in my services. The battery can't be faulty since the laptop works well unplugged. If the charger is faulty, how could it affect performance? Also, is there a solution where I don't have to buy a new one? – Wajih Aziza Sep 12 '13 at 15:55

It sounds like the charger circuitry is "confused" and thinks the battery has been removed (or is defective).

When you operate a laptop on charger only, with battery removed, it's often the case that the CPU is "throttled", since the charger typically can only supply 1/2 or 2/3rds of the peak power needed by the unit, with the battery being used to "fill in".

I'd suggest you first check all power-related settings (including those in any separate Dell utility) and attempt to reset things to "factory default".

Then (if you still have a problem), turn the unit all the way off, remove the battery, then boot only on charger & run a few minutes. (Maybe verify that the behavior in this mode is the same as what you're complaining about.) Turn off again, install the battery, and run only on battery for a few minutes, then plug in the charger and see how it goes.

It's vaguely possible that the battery is behaving abnormally, and so the charger is considering it to be "dead". Or the charger (or the laptop's power management circuitry) may be defective. (But I doubt the latter -- as a "last gasp" attempt I'd try running the battery down to 10% or less and then recharging for several cycles, to "reset" the charge detecting logic.)

share|improve this answer
Okay, here's what I found: 1) Power plug alone: The CPU can't go full power right away, only when demanded. 2) Battery alone: It goes up to maximum power. 3) Using both: It works like a charm but I mustn't remove the power cord or it will go back to being slow. – Wajih Aziza Sep 13 '13 at 2:43
1 & 2 I can understand. 3 is a problem since it defies the purpose of having a laptop – Wajih Aziza Sep 13 '13 at 2:46

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.