Now it's onto the board itself. If you don't really look too close, you may be forgiven for mistaking this board as the P55-UD6. However, there are a couple of subtle changes. The same full 30x24cm blue PCB is used that the P55-UD6 was based on and it's part of the Ultra Durable 3 line which includes 2 ounces of copper layered into the PCB to help cool it better.
The 24 pin ATX power connector is located in the same place behind the six DDR3 memory slots and yes, this board uses the same banking arrangement as the P55-UD6, so if you want to populate all six slots, the four blue slots can only have single sided memory. To be honest, this is more a waste of PCB space. The 4/8 pin EPS power connector is located in its usual spot behind the PS/2-USB combo tower.
GIGABYTE is one for keeping things powered. In fact, the new GIGABYTE top end boards come with 24 power phases for the CPU alone. That's extremely impressive from an overclocking stand point and this board would be ideal for clean voltages at ultra high speeds using LN2 cooled rigs. To keep things cool the Mosfets for the 24 phases are cooled by a heatpipe assembly that cools the P55 single chip, Southbridge/controller hub and the additional SATA controller chips.
Moving along, we have our storage connectors; this is where things change from the P55-UD6 which had six blue and four white connectors. There are six blue connectors, but only two white connectors. The reason for this is that the white connectors are run off a new Marvell PCI Express to SATA-III controller chip.
This chip is connected in to the board in a rather funny way. If you decide to run this chip, or the PCIe based USB 3 controller that the board also has, you will not only experience degraded graphics performance, but also one of the two chips must surrender to a x1 connection. How GIGABYTE has worked this is if you enable either chip at full speed, eight lanes for the lynnfield CPU's PCI Express controller (the same one that gives the graphics cards its PCIe connectivity) are diverted to the chip the user selects in the BIOS to run at the higher speed.
Unfortunately the P55 chipset itself has no PCIe gen 2.0 lanes on it and therefore doesn't have enough bandwidth to run either controller chip at full speed. Only X58 has enough lanes to run a graphics card at full speed as well as run both controllers at full speeds. This hopefully will be resolved in later revisions with a PLX PCIe controller bridge that ASUS is currently using to get around this problem.
Moving along to the rear I/O, things change a bit. You will notice that the board has the same eSATA/USB combo ports that the P55-UD6 introduced us to, coloured yellow, but there are two blue USB ports as well. These are the USB 3.0 ports controlled by the NEC controller chip. While we are on the subject of the ports, we must mention the 333 system that GIGABYTE introduced. 333 triples the power given to the USB 2.0, USB 3.0 and eSATA power ports. So rather than the max 500mA that USB 2.0 gives, GIGABYTE gives you 1500mA per USB port; more than enough to run an external 2.5" HDD on a single USB cable. USB 3.0 gets more power as does the power of eSATA; 3x as much as specified by the USB and eSATA standards. This is a huge plus.
Lastly, the slots. The layout configuration hasn't changed from the P55-UD6; three PCIe x16 slots are included which run 16/1/4 or 8/8/4, depending on what you want. However, if you enable either or both USB and SATA-III controller chips, the middle PCIe x16 slot can't be populated as the lanes from this are routed to the controller chips. Two PCIe x1 slots and two PCI legacy slots make up the final arrangement.