Prime Generator - some numbers

During my prime generation, I had the program write down what number prime (and prime) it was at each passing minute. Now, I've done a little bit of graphing and came up with these two graphs:

1) 12 hour test - I basically let the program run for 12 hours. This is the graph showing that:

graph showing that it goes slower the longer it runs

2) 1 hour comparison - I let the program run for an hour on two machines (one being my new, one being my old). This is the graph comparing the two:

graph showing the comparison between my new and old computer.

-UPTX