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. Usually on P55-based motherboards the manufacturer puts two PCI Express 2.0 x16 slots on the board, with the first slot working at x16 when only one video card is used or both slots working at x8 when two video cards are used, and this is the case of ASUS P7P55D Premium (P7P55D PRO, which we've already written about, comes with three PCI Express x16 slots, with the third one working at x4). ASUS P7P55D Premium also has two x1 PCI Express slots and two standard PCI slots.

This motherboard from ASUS supports both CrossFire and SLI configurations. Keep in mind that SLI support on P55-based motherboards will depend on whether the manufacturer licensed this technology from NVIDIA or not, i.e., not all P55-based motherboards have SLI support. On the ASUS line-up only P7P55D LE and the standard P7P55D do not support SLI.

click to enlarge
Figure 4: Slots.

Near the second PCI Express x16 slot (the light gray one) you can see the flash memory (on a small board installed perpendicularly to the motherboard) where the operating system and programs from Express Gate feature are stored (more on this feature later) and also a PCI Express switch chip from PLX, which is used to expand the number of PCI Express lanes available on the motherboard, allowing the board to accommodate all the extra features present.

In Figure 4 you can also see the on-board power and reset buttons, a feature that helps a lot especially when you are troubleshooting your PC.