What will you be doing with the SD card while it is out of the laptop?
System hardware specs and OS information?
I would expect Readyboost to work again.
If the laptop starts up and does not find the "ReadyBoost" SD card then the laptop probably just goes forward without ReadyBoost.
Is there really a noticeable performance difference with and without the "Readyboost" SD in and out of the laptop?