IT doesnt matter how you over clock it. with Rivatuner or just by enableing the hidden O/C tab in Nvidia's display panel. they do the exact same thing... just dont use more then 1 overclocking program at the same time, they could be both installed but dont change option in 2 programs at once..... i personaly just use the Hidden OC tab in Nv settings.
dont know about those games, iv only ran Doom'3 timedemo regaurding any game.
But i can probably take a guess at why your score is lower then that guys you linked to....
1 - he's overclocking. if you wont to compair your card at the same speed... he's only using a modest safe OC aswell, so you could just set your card to 580/1600(800mhz mem in options) and then run 3dmark.
2 - your score might still be a tad lower then his though because of your Cas3 ram, and he had a NF4 board with no onboard native display adapter... Dont know if that may also help his score or not.. but i do know Biostar is regarded by a lot of people as crap.
your score and performance in general though does not apear to me to be out of the norm. its just no ulra high performance because of some of the cheap parts of your system... witch i might add Aspire is a crappy PSU brand.
i assume your when you ran Q4 you had Antialiasing and AF way up too? right... cause low FPS with all that **** maxed isnormal, buf if you were using max setting without AA, then that is not normal.