I've got an Intel Core i5-2500 in an Asus P8Z68-V LX S1155 Intel Z68 DDR3.
The motherboard has on-board (Intel) graphics with VGA / DVI / HDMI but I thought it would be better to use a PCI Express graphics card with it's own RAM to keep processing/memory separate from the system so I put in an AMD 5450 850M 1GB DDR3 PCI Express card (wasn't too expensive but I don't play games so I don't need something mega powerful).
However, comparing the Windows 7 system scores between the on-board and the ATI, the on-board is better.
I dual boot with Windows 7 and Linux.
Am I better off with the on-board Intel?
Is there a way I can use both the on-board and the ATI at the same time so I can use both HDMI ports? - putting the PCI-E one in seems to disable the on-board.
5450 is a very low card. I also dual boot Ubuntu and windows 7. But that doe not matter regarding to what graphics option to use. You can not use both HDMI ports. You can do that only in SLI, CFX or dual graphics.