MULTI-LEVEL SYSTEM MEMORY CONFIGURATIONS TO OPERATE HIGHER PRIORITY USERS OUT OF A FASTER MEMORY LEVEL

A method is described. The method includes recognizing higher priority users of a multi-level system memory characterized by a faster higher level and a slower lower level in which the higher level is to act as a cache for the lower level and in which a first capacity of the higher level is less than a second capacity of the lower level such that caching resources of the higher level are oversubscribe-able. The method also includes performing at least one of: declaring an amount of the second capacity un-useable to reduce oversubscription of the caching resources; allocating system memory address space of the multi-level system memory so that requests associated with lower priority users will not compete with requests associated with the higher priority users for the caching resources.