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

I have a Thinkpad laptop W510 running Linux Ubuntu 12.04 with NVidia drivers, connected to an external 24" Eizo screen via displayport. The screen behaves ok under normal conditions, but if the CPU usage is pumped up to maximum, the external screen starts flickering every 30 seconds, pretty regularly, only once (that is, it's not a constant, repeated on/off/on/off flicker, it's a short single burst that may appear as a dark bar somewhere, lasting a fraction of a second).

If the CPU usage goes down to normal, no problem. If it climbs up again, it starts again after a couple of minutes. Cabling is perfect.

Where is the problem, and how can it be fixed?

share|improve this question
Have you tried different drivers? – James Mar 8 '13 at 9:24
up vote 2 down vote accepted

Have you looked into PowerMizer? Every "ubuntu nvidia flicker" discussion I can find seems to reference it for years.

For example:

share|improve this answer
This indeed seems to be the reasonable answer. I'll try it out, but you definitely gave me a good hint – Stefano Borini Mar 12 '13 at 11:37
Curious if this ended up being the culprit ... . – LilCodger Mar 18 '13 at 19:00
We tried again, and apparently the problem didn't show up. It might have been a random fluke, but with now 5 screens and 5 laptops all with the same setup, we haven't incurred in the problem again. I personally disabled powermizer, but the others didn't. – Stefano Borini Mar 18 '13 at 20:50

From what you describe I guess the laptop doesn't provide enough power to the monitor. CPU consumes more power when its usage is high and screen starts to flicker.

You can do few things to find out what causes the problem. First I would try another cable and port, second thing to do it to replicate the problem with different OS.

share|improve this answer

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.