The maximum size of the Flash Pool cache per system is a function of the controller model and the Data ONTAP release in use. In addition, when both Flash Pool and Flash Cache are used on the same system, the maximum cache size for each caching solution applies, as does the total maximum cache value for the combined use. For details refer section 3.3 Maximum Cache Capacities of the TR-4070. You can refer Hardware Universe to get the specifications for the controller model that you are currently using.
For eg: I have pasted a copy of the limits for the FAS 8060 controller running cDOT 8.3.1.
So even if your system has more cache, only the allowed maximum will be used. Hope this helps.
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