PCB Design and Functionality
We have already talked about the new look of Intel P55 Express based mainboards in our Asus P7P55D Deluxe mainboard review. However, Gigabyte GA-P55-UD6 reminds us of the past days. At first glance it seems that it is just another mainboard modification on the old Intel X58 Express chipset. Six DDR3 DIMM slots contribute most to this initial deception. However, don’t be misled, LGA1156 platform supports only dual-channel memory access.
By the way, the situation with memory is not so simple. Formally, it is an advantage to have six DIMM slots onboard, but you won’t be able to increase the memory capacity above the supported maximum anyway. Gigabyte GA-P55-UD6, just like other mainboards with only four memory DIMMs, supports 16 GB of RAM maximum. In other words, the primary advantage of this mainboard is that it allows using more memory modules of lower capacity. If you decide to use all six memory slots, then you will have to keep in mind certain limitations, such as the need to use single-sided DDR3 DIMM modules.
The cooling system with heatpipes is also built according to seemingly traditional plan: South Bridge, North Bridge, a couple of additional heatsinks over the processor voltage regulator components. However, we know that the North Bridge functions of Intel P55 Express chipset have been moved over to the CPU that is why the cooling system that may look familiar on the outside has a completely different internal structure. Gigabyte GA-P55-UD6 mainboard has an enormous number of additional onboard controllers. Besides six SATA ports provided by the chipset, we see another four on one side of the PCB. Two SATA and one PATA port are implemented via Gigabyte SATA2 controller and another two appeared thanks to JMicron JMB362 controller. These two microchips that do not run very hot at all are cooled with a pretty large heatsink located where the South Bridge would normally be. Moreover, there is a heatpipes that leads from this heatsink to an even larger central heatsink over the single P55 Express chip. The second heatpipe that starts at the base of the chipset heatsink goes through two additional heatsinks over the processor voltage regulator MOSFET.
No doubt that this massive and strongly ramified cooling system is surplus. It is absolutely unnecessary the way it is, since the chipset and additional controllers dissipate very little heat. Its major function is not cooling but creating the proper strong and powerful impression from Gigabyte GA-P55-UD6 mainboard. The same reason obviously lies behind the increased number of phases in the processor voltage regulator circuitry: there are 24 of them. Luckily, the mainboard knows how to vary the number of active voltage regulator phases depending on the current CPU utilization. Another advantage that the board inherited from the predecessors – twice as thick conductive layers. Due to thicker conductive layers the resistance of the mainboard conductors got lower, which in its turn means that the electronic components will receive more stable power supply. Moreover, thicker metal layers improve microchips heat transfer and dissipation.
Gigabyte GA-P55-UD6 mainboard, just like Asus P7P55D Deluxe, is equipped with three graphics card slots that work according to the same structure. Only the top slot can provide full PCI Express 2.0 x16 speed. As soon as you install the second graphics card into the second slot, the bandwidth gets cut down in half. The last connector works at PCI Express x4 speed maximum.
The connectors on the back of Gigabyte GA-P55-UD6 mainboard are especially interesting. They look very unusual. At first we see two USB ports and a universal PS/2 port for keyboard or mouse. Then come the optical and coaxial S/PDIF; the sound on Gigabyte GA-P55-UD6 is implemented via Realtek ALC889A codec. Two local network connectors are also quite common, they are provided by two Gigabit Realtek RTL8111D controllers. And so are the two IEEE1394 (FireWire) connectors implemented via Texas Instruments TSB43AB23 controller; the third port is available as an onboard pin-connector. Two yellow ports in the middle are the regular USB ports, while two lower ones are eSATA ports implemented via another JMicron JMB362 controller. However, these are not standard eSATA. These are the so-called “Powered eSATA” or “eSATA/USB Combo” – the ports that combine eSATA and USB. We saw connectors like that for the first time on ASRock mainboards and now they become widely spread due to additional convenience that they bring to the board. They can be used like the regular USB ports, and the flash-drives with eSATA interface connected to these ports do not require additional power as they receive it though USB.
The complete list of Gigabyte GA-P55-UD6 technical specifications looks as follows:
We would like to wind up our design discussion with a schematic components layout:
Overall, the PCB design of Gigabyte GA-P55-UD6 mainboard can be estimated as moderately good. Among the advantages we should mention Power On, Reset and Clear CMOS buttons and a POST-code indicator panel. Among the drawbacks, we should list not the best location of the FDD and IDE connectors. The cooling system looks unjustifiably complex, but this is not the only thing that indicates superfluity. I am sure that very few people will need six DIMM slots, two network controllers and twelve SATA hard drives that can be connected to this board. However, not everything will eventually go for a flagship solution and having extras is anyway better that missing something, so we will forgive Gigabyte GA-P55-UD6 these extravagances.