Know the performance of the smartphone

I'm working with the data generated with the sensor accelerometer. I save every sensor event in sqllite. I don´t have any problem With smartphones like Nexus 5 but with old devices, I think that not all the registers are being recorded in the database because the smartphone doesn´t have enought capacity. I'm thinking in save all the sensorevent in an array and then save all of them with a transaction, but only for the old devices. How can I know the capacity of a smartphone or at least the year? Thanks, Manuel