Just like any other component in a server stack, it is important to be able to isolate the performance of each server to granularly test small configuration changes. Apache ships with ab for this purpose. Memcached has the memslap program provided by libMemcached. To run tests, we'll start two small Memcached servers on the local machine -
$ memcached -d -m 256 -p 11211
$ memcached -d -m 256 -p 11211

Now we'll run a test to see how the binary protocol affects the performance of our Memcached server. First we run the test without the --binary flag, then with -
$ memslap --servers=127.0.0.1:11211,127.0.0.1:11212 --concurrency=100 --execute-number=10000 --initial-load=10000 --flush
Threads connecting to servers 100
Took 42.635 seconds to load data
$ memslap --servers=127.0.0.1:11211,127.0.0.1:11212 --concurrency=100 --execute-number=10000 --initial-load=10000 --flush --binary
Threads connecting to servers 100
Took 32.220 seconds to load data

From this test we can see that enabling the binary protocol increased performance by approximately 25%. These metrics would be otherwise hard to calculate without a dedicated Memcached benchmarking tool. To see a complete list of options for memslap, run
memslap --help