I have an older C840 I use for some compatibility things and a spare. For a couple months, it's been slowing down, from 2.2 ghz to 1.1. While this doesn't sound like much, it makes the computer essentially unusable. Even typing is like waiting for paint to dry.
I installed Speedswitch, but that has no effect. It shows the CPU at full speed when it's running fine, but when it goes to compatibility speed, the "max speed" also shows only ~1100 mhz. Nothing I do can make it come back up. I have to shut it off and hope to get lucky the next day.
Disabling Speedstep in the BIOS has no effect.
The only possible symptom is that sometimes the 2nd fan shows to be only running at ~1900 rpm. However this is not a direct correlation to slowdown. But it's the only symptom I can find of something potentially wrong. And I should add TEMP has little to do with it. Sometimes the laptop will run for hours and get over 80 C and still be fast, and sometimes it starts out from a cold start, never getting over 59, and never reach full speed
I'd like to get this solved, since the laptop is still of some use.
Note: I also pulled the CPU, blew it off with compressed air, and re-seated it.