Gucky
for NDS it could help to deactivate the rewind-function.
for 3DS you need a modern CPU with at least 2.5GHz and a powerful GPU.
so i guess the CPU/GPUs of your Notebooks are not performant enough for 3DS emulation.
Notebook CPU/GPUs in general are less powerful then equivalent Desktop variants.
did you also test Dreamcast and Gamecube games?
from my experience PS2 and 3DS emulation are the most demanding for CPU/GPU.
then comes Gamecube, NDS
and then Dreamcast, PSP and N64.
when your systems already struggle with Gamecube and NDS, then 3DS and PS2 emulation won't work very well also (maybe some less demanding 2D games will work)
what are the hardware specs of your systems in detail? which CPU and GPU models do they have?