I suspected a bug on our "big" PC (AMD 2X2.7G 6G ram soon to be 8G) so I ran MWBytes.
It found 12 items which I got rid of and then forgot about it. Sometime
later I ran a Samplitude track of Discovering Music (son analyses them)with Task Manager
to see how much ram was being used. I also put up DPClat and horror! My normal 20muSec
latency with ab max spikes of 250muSecs shot up to an angry red 2mSecs! And I was told
there was badness in the works. I uninstalled MWB and all is calm and peaceful
again. Now I know we are told that anti-V software can do bad things but I have Msoft SE
and it is never a problem.
The Microsoft offering is so bad it's not worth having. It missed everything, so I'd never
say "it takes care of".
Malware Bytes is very good at finding malware, but it
has a stay-resident portion which is a bit of a resource hog as you've found out. You can
install it without that portion and just use it as a secondary check.
Eset NOD32 which is exceptionally good at detecting viruses and seems to use very little
by way of resources. To be honest I'd turn off the AV during low-latency recording anyway
- in fact I generally just unplug the network and disable AV etc. if doing serious work on
anything audio or video.