Traceflag 758 enables the use of large (4k, 8k and 16k pages) chunks of memory in Engine Local Cache (ELC). This feature was introduced under CR 652106-2 in ASE 15.7 ESD 2 and higher.
It is typically used to reduce very high spinlock contention for Resource->rproccache_spin (shown by sp_sysmon).
This traceflag should be activated by adding '-T758' as a dataserver parameter in the RUN_SERVER file and the rebooting ASE.