What is intelligent stream scanning in avast 2015 ???
a google search say…
Unlike most competitive solutions, Web Shield’s impact on browsing speed is almost negligible. This is because of a unique feature called “Intelligent Stream Scan” that lets the Web Shield module scan objects on-the-fly, without the need of caching. Stream scanning is performed in operating memory only (without the necessity to flush the contents to disk), providing maximum possible throughput.