Should benchmarks (to compare processors performance) be compiled with optimization CFLAGS?

I need to compare performance of 2 processors and I concluded I should benchmark then with several various tests.

I'm currently using

• linpack (HPL) (because it's still well known and used for example to build top 500 list)


• SciMark2 (because of 5 different methods inside)


• simple for loops written in C (to see difference between simple instructions / more sophisticated calculations)

Compiling them I saw huuge difference in performance if they are compiled with some *FLAGS (-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong --param=ssp-buffer-size=4).

Should I be using these optimization flags or not to get my point?

I'm afraid I'm loosing some point / differ benchmarks between architectures when optimizing.