symfony - Symfony2 JMSSerializer performance issue -

i'm using jmsserializer on jsonrpc symfony2. 1 of request return more 980 results (with references). request take 210ms executed, pretty fine, serialization take more 30 seconds response weight of 35mb. idea how improve ?

edit : need datas in response, no exclude or maxdepth policy required.

all interfaces relationships , collections of entity serialized. common explanation of this. should not try serialize , make sure configure primitive , scalar types serialized.