I'm looking at using a Nofan CR-95C processor heatsink with a Gigabyte GA-Z87MX-D3H (e.g. from QuietPC who build systems this way, see http://www.quietpc.com/sys-a460). However, I occasionally want to play 3D games and would like to use a discrete GPU, and the heatsink is large enough to typically block PCI express slots.
It looks from the GA-Z876MX-D3H spec that either a PCI Express 3.0 16x slot with 8 lanes or a PCI express express 2.0 16x slot with 4 lanes might be the only ones that would not be obscured. If I put something like a ASUS HD7750-DCSL-1GD5 in those slots what kind of performance might I get, relative to the integrate HD4600 graphics on a 4770K or that card running in the PCI express 3.0 16 lane slot?