You can drop a buffer pool by setting its size to 0. The memory from this pool is added to the default pool. To drop pool 4k from named cache tempdb_cache, at instance SALES_INSTANCE:
sp_poolconfig 'tempdb_cache','0','4K' go sp_poolconfig 'tempdb_cache' go
Cache Name Status Type Config Value Run Value --------------------------- ------ ----- ------------ ------------ tempdb_cache Active Global,Mixed 100.00 Mb 100.00 Mb (1 row affected) ------------ ------------ Total 100.00 Mb 100.00 Mb ========================================================================== Cache: tempdb_cache, Status: Active, Type: Global,Mixed Config Size: 100.00 Mb, Run Size: 100.00 Mb Config Replacement: strict LRU, Run Replacement: strict LRU Config Partition: 1, Run Partition: 1 IO Size Wash Size Config Size Run Size APF Percent -------- ------------- ------------ ------------ ----------- 8Kb 1632 Kb 8.00 Mb 8.00 Mb 10 2Kb 18840 Kb 0.00 Mb 92.00 Mb 10 (return status = 0)