Sybase IQ runs most efficiently when it knows how many physical CPUs are available to it. On a machine with hyperthreads turned on, or where IQ is unable to access all of the available CPUs, IQ will create too many threads and run less efficiently than it should.
Start the server with -iqnumbercpus set to the number of CPUs available to IQ, overriding the physical number of CPUs. For details, see the -iqnumbercpus server option in Chapter 1, “Running the Database Server” in the Sybase IQ Utility Guide.
