What you're doing is:
issue some draw calls
This is completely and utterly wrong.
I'll give you an analogy that should make it a lot easier to understand. Lets say you have a 1MB and a 100MB lan and you want to write a benchmark to compare how fast you can download a 1GB file on both of those, so you do:
start download of a huge file
Do you see the problem? Obviously the file hasn't been downloaded by the time you stopped the timer. What you effectively measured is the speed at which you can execute function calls.
And yes, while your original suspicion that the 100MB line is a lot faster is still likely true, your test in no way proves that. In fact it does nothing short of making some poor individuals very sad due to the state of computer science. Also "So what that the test is wrong, it still feels faster" is not a valid excuse, because the whole point is that the test is wrong.
To give your tests some substance always make your applications run for at least a few seconds reporting the frames per second.
Or even better don't write them. Somewhere out there, some people, who actually know what's going on, have those tests written. And those people, who just happen to be "graphics people" have reasons for making certain things default. So while you may think you've made this incredible discovery, you really haven't. There's a kde-graphics mailing list where you can pose graphics question.
So to the next person who wants to write a KDE graphics related blog/article please, please go through kde-graphics mailing list first.