Hello all, I added a new application measuring the compared throughtput of the synchronized primitive versus fair and unfair locks. Here are the results. java.runtime.version = 1.6.0_11-b03 java.vendor = Sun Microsystems Inc. java.version = 1.6.0_11 os.name = Linux os.version = 2.6.25-gentoo-r6 Sync: 139698775, or 35 nanos per cycle Unfair: 87028802, or 57 nanos per cycle Fair: 4106449, or 1217 nanos per cycle java.runtime.version = jvmxa6460-20081105_25433 java.vendor = IBM Corporation java.version = 1.6.0 os.name = Linux os.version = 2.6.25-gentoo-r6 Sync: 356946629, or 14 nanos per cycle Unfair: 91892449, or 54 nanos per cycle Fair: 7380308, or 677 nanos per cycle As you can see there is a substantial difference in throughput. The ration is about 40. Cheers, -- Ceki Gülcü Logback: The reliable, generic, fast and flexible logging framework for Java. http://logback.qos.ch