Write performance regression in replicated non-transactional mode

<infinispan xmlns="urn:infinispan:config:8.0">
    <jgroups>
        <stack-file name="jgroupsStack" path="jgroups-udp-custom.xml"/>
    </jgroups>
    <cache-container name="default" default-cache="testCache">
        <transport stack="jgroupsStack" lock-timeout="600000" cluster="default" />
        <serialization></serialization>
        <jmx> <property name="enabled">true</property> </jmx>
        <replicated-cache name="testCache" mode="SYNC" remote-timeout="60000" statistics="true">
            <locking acquire-timeout="3000" concurrency-level="1000" />
            <state-transfer timeout="60000" />
        </replicated-cache>
    </cache-container>
</infinispan>