Slow response using live persistence

After not using linux for a while, I decided to roll back to kali for pen testing. I burned kali 2019 on a USB drive 16GB and set persistence. The persistence partition is about 11GB (Ext4) the rest being the operating system itself. As you can tell by the title, kali is running EXTREMELY slow. Opening up a console and using tools from the terminal like msf or nmap is fine. Launching any tool with the GUI like maltego or Armitage lags so much, that it takes 3 minutes for a window to pop up. Even opening files or changing the wallpaper takes from 30sec. to 1min. Firefox ESR will almost definitely crash unless I wait 2 minutes between each click and close the "Firefox is not responding tab" 20 times. I have 8GB of Ram and an i3 core 2.6GHz. Could it be the read/write speeds of the usb (2.0, not sure about speeds), does the size of the partition that has the OS files in it affect the speed (maybe I should leave some room when resizing)? I tried running it live without persistence and it's still very slow. Any ideas?

Have you tried a different thumbdrive? Some may be quick for the first few seconds but take forever, because crappy flash chips and small cache.