If you have contention for the LRU latches, then raising the number of latches will normally be helpful. There is very little negative feedback from using a generous number of LRU latches, so going all the way up to the maximum (2 * cpu_count at 7.3) is fine. However, if you don't have any contention for the LRU latches then the db_block_lru_latches parameter should be allowed to default.

We have NUMA-Q server with 16 CPUs hosting several, generally OLTP, databases (v7.3.4.4). Oracle recommends setting db_block_lru_latches to 16 (the number of CPUs). On a server which hosts this many databases, is this recommendation still valid?