If your child has processing issues on the WISC-IV, the tester can calculate the GAI, which takes out the effect of processing speed and working memory. If slow processing really is an issue for your son, that would be good information to have, as if it is a real bottleneck, he might need a 504 plan and accommodations of extra time, decreased copywork, etc., so that the volume of work doesn't get overwhelming as he accelerates.