: I'd move to SolrCloud 4.2.1 to benefit from sharding, replication, and : the latest Lucene. How many queries you will then be able to run in : parallel will depend on their complexity, index size, query : cachability, index size, latency requirements... But move to the : latest setup first.
No to mention thta geospatial query support is vastly improved in Solr 4.x vs what was possible in Solr 1.4. -Hoss
