One of the main new features from socket LGA1156 processors is the presence of an integrated PCI Express 2.0 controller inside the CPU. This controller supports one x16 connection or two x8 connections. The Intel P55 chipset provides a total of eight x1 PCI Express lanes.
On an unusual configuration for a traditionally price-oriented company, ECS added very high-end components on their P55H-AK, an NVIDIA NF200 bridge and a PLX PEX8608 chip. The first chip adds 32 PCI Express x1 1.0 lanes, while the second chip adds eight PCI Express x1 2.0 lanes.
These two chips allow the three PCI Express x16 slots to work at x16, x8, and x8 all the time, plus prevent performance from dropping when you run two or three high-end video cards, SATA-600 hard disk drives and USB 3.0 devices at the same time. On motherboards without bridge chips, performance may drop under this type of load, as the chipset doesn’t have enough PCI Express lanes to connect all these devices at the same time at their full speed.
The three PCI Express x16 slots support CrossFireX and SLI configurations.
The ECS P55H-AK also has two PCI Express x1 slots and one standard PCI slot. There is enough space between the first two PCI Express slots for you to install in the first slot a video card that takes up to three expansion slots without “killing” the second slot. If you install a dual-slot video card in the first PCI Express x16 slot you won’t kill any of the PCI Express x1 slots available, a configuration rare to be seen.
On the other hand, if you install a dual-slot video card in the second PCI Express x16 slot, you will “kill” the standard PCI slot, and you can only install a dual-slot video card in the third PCI Express x16 slot if you have a case with eight or more expansion slots.