25% of physical memory
1% to maximum amount of physical memory
When using NCA on a system with a lot of memory (greater than 512 Mbytes). If a system has a lot of physical memory that is not being used, increase this parameter so NCA will efficiently use this memory to cache new objects, and therefore, increase system performance.
This parameter should be increased in conjunction with nca_vpmax unless you have a system with more physical memory than virtual memory (a 32–bit kernel that has greater than 4 Gbytes memory). Use pagesize(1) to get your system's page size.