What is the best bang for the buck for a Acer AX3400G-U4802 all stock right out of the box , price really doesn't matter , I really don't what to change the power supply , I've already bought a XFX R7750 core edition and tried to install it but I can't get it to work don't know what's up with that , So I just want the best low profile video card my desk top can handle