av-test.org/no_cache/en/tests/test-reports/?tx_avtestreports_pi1[report_no]=133160
Proves my words… Avast has improved a lot of the backend in these month…Great Job! Avast team. ;D
Here is Microsoft Security Essentials v. 4.2 & 4.3 used as the baseline for all scores and rating: http://www.av-test.org/en/tests/home-user/windows-7/julaug-2013/
Scroll down to the last a/v listed to find MSE.
Avast is getting very heavy, ain’t looking good 
They are working on their engine for Avast 2014, here was version 8 tested,.
Does it run heavy on actual systems here?? No…
is that weird? Yes!
Doesnt happen with others here…so its your machine
If you bothered too read the thread, you would see that its not my machine :
I already uninstalled Avast from 3 pcs cause of this spikes during YT video playback, i know for sure its Avast. It was in version 7, and its now again.