To be absolutelly certain that your expensive machine isn't doing the job, I suggest downloading the test file from the forum's Video Card Database and running the file using the same settings on both machines.
Without teaching my Grandma how to s u c k eggs, are both machines actually imaging in OpenGL or did the new one come up using the internal engine instead?
I suspect, however, that your new machine has different, more demanding OpenGL settings than your old machine does.
For instance:
-- OpenGL window size made much bigger on new machine.
-- All smoothness, texture and other OpenGL features turned on.
-- OpenGL distance resolution closer in old machine.
Dwight Atkinson