The virus can do a variety of things, from taking over hard disk space to getting access to your personal information or draining your CPU. There are a myriad of anti-virus applications on the market to protect your devices from these issues. It is crucial to select an antivirus program that will have a minimal impact on your system’s performance. This is a key factor that all of our antivirus products are tested against. The results below are based on the amount of time it takes each program to perform an operation. For instance, Kaspersky Security Cloud Free had a background impact of 6.6% when it was running an entire scan, while ESET had a slightly higher impact of 12%.
Avira is a German-based company. Avira is a reputable company in our tests and consistently scores above the 90% mark in all three categories: Performance, Protection and Usability (False Positives). Its user interface is comfortable and has a wealth of functions, including a clever firewall as well as a variety of privacy tools. Avira subscriptions are priced monthly rather than for a fixed time period of 1-3 years. This makes it easier to cancel your subscription or make changes at anytime.
Essentware, formerly known as PCKeeper was a relatively new name in our tests. It utilizes the Avira Engine under the hood. Overall, it scored well. Its performance and user interface are both user-friendly, but a few stability problems such as scan jobs freezing up that have led to a lower rating. The detection was great and a flawless run of the certification sets earned VB100.
http://www.avastantivirusreview.com/avast-use-high-cpu-what-you-should-do