Computational minibatch size in Refinement

Hello,

During refinement, the default value for Computational minibatch size is 2000. The description states that 1000 should be good but if enough RAM is available it can be increased to 4000 to increase computational performance.

My question, what exactly is Computational minibatch size? Also, if we have a lot of RAM is it viable to increase the value to 6000+?