Yeah, and it may be worth checking if you have antivirus software running that could interfere with the FMS computations. There is some of that going on starting at lift-off, and you may have modified the routing/performance calculation unknowingly (like entering a new weight) and not executing it. So the FMS is constantly recalculating the modified routing. If antivirus checking interferes with this, the slowdown happens.
I know many people are VERY worried about disabling live antivirus checking, and they frown upon excluding a folder from checking, but it may be worth just trying to test if that is the cause. We are still looking at options to remove this adverse effect of database accessing.
Cheers, Jan