[AC Question]

Hey. I have installed CPU-Z a long time ago on my Nexus 5. Lately the CPU load has been strange. I'm looking at cpu-z right now and I only have Whatsapp open but it still says 300mhz on CPU 0. Then sometimes it will hit on all four CPU's 2,27GHz!!
My phone is not laggy or anything but this is weird. CPU load is anywhere from 8% to 50% all the time, most commonly on 20-45%. Also, I only have 17% ram (318mb) available. Is this also something to worry about?

I have not downloaded any apps from 3rd market places. I don't use antivirus on Android, but I've tried Avast - it said no virus and Malwarebytes says the same.

A while back I tried Advanced Task Manager which allowed me to remove permissions from app (no root required and yes my phone is not rooted, just Android 5.1) and then it reinstalled them. To reinstall them, I had to enable allow downloading from unknown sources. For example my Power Amp couldn't work then because it was a modified apk.

Any solution to this?

I also have a call quality problem. I can't hear other people very well when I talk - especially if I call someone and theres some background noise, such as people talking.

[B. Diddy]

Welcome to Android Central! I doubt you have a virus. Viruses are still very uncommon, and require you to actually accept the installation of the malware. So as long as you haven't been randomly accepting downloads and installations from shady sites, you should be ok. In addition, Google can periodically scan your apps for you, if you open the Google Settings app, then Security, and turn on Verify Apps.

I'm not an engineer, but I wouldn't be too surprised by that kind of CPU behavior. The phone is often doing things in the background, like refreshing data with the web, or checking location. Any kind of activity like this might cause brief spikes in CPU usage. I also wouldn't necessarily trust CPU-Z's RAM usage figure--I've found that "RAM booster" apps often take up a fair chunk of RAM themselves, so that the free RAM you see reported there is significantly lower than what the system reports. Try this--see how much free RAM CPU-Z is reporting, then go to Settings>Apps>Running and see how much free RAM the system reports. I just did that, and CPU-Z reported about 460 MB of free RAM, while the system reported double that (around 850 MB).