I believe TieredCompilation was disabled by default on Java 7u55:

    $ java -server -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version|grep TieredCompilation
         bool TieredCompilation                         = false           {pd product}        
    java version "1.7.0_55"
    Java(TM) SE Runtime Environment (build 1.7.0_55-b13)
    Java HotSpot(TM) 64-Bit Server VM (build 24.55-b03, mixed mode)

I would be interested in hearing from people with first-hand experience disabling TieredCompilation on Java 8 on production servers.