A method, system and computer program product for managing an amount of storage written from a transaction group comprises creating a plurality of transaction classes within each of a plurality of write transaction classes and discovering an initial underlying drive capability assignable to the transaction classes when a storage pool is allocated (SPA). Each transaction class capability weight is adjusted via computing an instruction and operations per second, a data rate per second and a time slice at every storage pool allocator sync time. An unspent time slice from an adjusted transaction class is lent to a plurality of remaining transaction classes yet to be adjusted via a staged processing distribution during sync of the SPA. The disclosed method further includes assigning system resources and underlying drive capability to each transaction class per its capability weight based on a ratio of weights for each transaction class of operations.