try using parallel with 'classes','methods', and 'both' values?
include useUnlimitedThreads=true
http://olafsblog.sysbsb.de/concurrent-execution-of-integration-and-unit-tests-with-maven/
"While there are more parameters to adjust, the default configuration (two threads per core) seem decent. Also, my measurements strongly suggest that parallel execution of classes is significantly faster (around 30% – 50%) for normal test cases than parallelizing on a per-method basis. However this may change if you have few classes with many long-running methods."
http://maven.apache.org/surefire/maven-surefire-plugin/examples/fork-options-and-parallel-execution.html https://weblogs.java.net/blog/johnsmart/archive/2010/07/06/running-junit-tests-parallel-maven
http://olafsblog.sysbsb.de/concurrent-execution-of-integration-and-unit-tests-with-maven/ "While there are more parameters to adjust, the default configuration (two threads per core) seem decent. Also, my measurements strongly suggest that parallel execution of classes is significantly faster (around 30% – 50%) for normal test cases than parallelizing on a per-method basis. However this may change if you have few classes with many long-running methods."