25% of virtual memory
1% to maximum amount of virtual memory
When using NCA on a system with a lot of memory (greater than 512 Mbytes). If a system has a lot of virtual memory that is not being used, increase this parameter so NCA will efficiently use this memory to cache new objects, and therefore, increase system's performance.
This parameter should be increased in conjunction with nca_ppmax. Set this parameter approximately same as nca_vpmax unless you have a system with more physical memory than virtual memory.