Hmm... As Ben notes above, threads can be done poorly too. IBPhoenix (the current name of the company which was supposed to take over the interbase stuff from inprise) has some interresting documents on their website. A
KnowledgeBase Article by Ann Harrison herself describes that the interbase superserver (=the threaded server) has such a sucky thread implementation (threads can't execute in parallell) that it cannot take advantage of SMP, leading to only 5-20% better performance on a 2-way system. And performance degradation on NT because NT is so smart that it notices that one processor is idle, switches the database process to the idle processor, then notices that the first processor is idle and switches the database process back to it etc... :)
