The Avira Antivirus Web Protection module works like an HTTP proxy and needs a cache to verify received data sequences.
After scanning, the cached data is forwarded with maximum speed to the internet browser. The Avira Web Protection module works very fast, with the search process only having a negligible impact on the download speed.
For the purpose of caching data, the Web Protection module works at around half speed until 50% of the download is complete. After that point, it then works at full speed. Therefore, the estimated download time remains the same in most cases.
However, the short delay to delivery at the start gives the impression that the speed is lower.
For the same reasons, website and test program speed measurements provide inaccurate results.