Is it possible to speed up maven artifacts downloading?

I know its an old question, but stumbled here from Google. I already had proxy in place, just needed to speed up with concurrent downloads. You can using mvn option:

-Dmaven.artifact.threads=30

Source:
https://maven.apache.org/guides/mini/guide-configuring-maven.html

Configuring Parallel Artifact Resolution
By default, Maven 2.1.0+ will download up to 5 artifacts (from different groups) at once. To change the size of the thread pool, start Maven using -Dmaven.artifact.threads. For example, to only download single artifacts at a time:

mvn -Dmaven.artifact.threads=1 verify
You may wish to set this option permanently, in which case you can use the MAVEN_OPTS environment variable. For example:

export MAVEN_OPTS=-Dmaven.artifact.threads=3