After the last update, the firefox started to load the processor heavily. One core is constantly employed almost 100%.
firefox loads cpu 50-100%
@joekamprad didn’t help
it seems, option “layers.acceleration.force-enabled” in about:config causes such problems. I put it in a true position in order to avoid tearring with the video card nvidia gtx760. After the option was returned to the false position, processor overloading stopped.