Upon starting up your Linux kernel, a bogoMIPS calculation will be made and recorded into /proc/cpuinfo. This is a value that is not dynamically updated, so if you change the clock speed of the CPU, the bogoMIPS value contained in /proc/cpuinfo will not be updated. If all you’re interested in is a simple verification that your CPU speed was changed, you could compile and run the following bogoMIPS calculation program both before and after the clock speed change.
Simply call ‘make’ to compile the program. You may need to modify the Makefile in accordance to your needs (cross compiling, gcc flags, etc). You may notice that the bogoMIPS value calculated by this program is not the same as the value calculated by the kernel. That’s okay. What matters here is that you can verify a change in CPU speed. After all, “bogo” stands for “bogus” which simply means “fake”.