Hi hstr,
Typically when we do benchmarking, we benchmark the cryptography algorithms versus benchmarking a send or recv that would include I/O operations. The underlying cryptography is going to be the most performance intensive operations of the SSL/TLS connection, where sending or receiving data over a network or transport medium is going to have many more factors in play than the SSL/TLS library.
We ship a crypto benchmark application with wolfSSL, located in the <wolfssl_root>/wolfcrypt/benchmark/benchmark.c file. If you are compiling this on an embedded platform, you can define NO_MAIN_DRIVER to compile out the main() from benchmark.c if you have your own driver/main(). You can also define BENCH_EMBEDDED when compiling the library/benchmark.c to use less memory. benchmark.c contains individual crypto benchmark functions (ex: bench_aes(), bench_rsa(), etc.) which can be called individually, or you can call benchmark_test() which will call all of the enabled crypto benchmarks.
Going back to your mentioned benchmark, do you know if both connections were using the same cipher suite, key length, and application code?
Thanks,
Chris