How to upgrade a Cisco 3945 to a 3945E ?

[Emma Jing]

I have a Cisco 3945 router and i want to get somewhat high CPU usage to make its speed faster and faster.Is upgrading this thing as simple as buying a SPE-250 and pulling the SPE-150 out?

[EINSTEIN_007]

You can try to check the ISR G2 Performance Overview for both the versions from the below link which will give you a clear idea:
https://supportforums.cisco.com/serv...Perfomance.pdf