Gigabyte P55-UD6 Motherboard
By Rafael Coelho on November 9, 2009


P55-UD6 is the top shelf motherboard from Gigabyte for Intel socket LGA1156 processors (Core i5 and Core i7). Let's take a look at this motherboard, with twelve SATA-300 ports, six memory sockets, support to SLI and CrossFireX, 24-phase voltage regulator and more.

P55-UD6 box deserves some attention. First because it is twice as tall than common motherboard boxes. It has a shiny look, with a very cool texture. The upper side is actually a door that, once opened, allows you to see the motherboard. Inside the box there is a plastic box that holds the motherboard, and a cardpaper box with manuals, accessories and cables, which justify the double high box.

Gigabyte P55-UD6
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Figure 1: P55-UD6 box.

Gigabyte P55-UD6
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Figure 2: Fake cover.

Gigabyte P55-UD6
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Figure 3: Box contents.

Looking at the motherboard, we immediately see the cooling system, with heatpipes connecting the voltage regulator transistor heatsink, the chipset and another heaksink that seems to be the southbridge cooling solution. But P55 chipset does not have a southbridge! In next few pages we will see what that heatsink cools.

Gigabyte P55-UD6
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Figure 4: Gigabyte P55-UD6.


One of the main features of the socket LGA1156 CPUs is the presence of a PCI Express 2.0 controller integrated into the processor. This controller supports a x16 connection or two x8 connections. P55-UD6 seems to have three PCI Express x16 slots, but looking carefully we see only the first one is really x16. The second slot works at x8 speed, and is good to remember that, if you install a video card on it, the first slot works also at x8.  Third slot is actually a PCI Express x4 slot controlled by the chipset. You can install a regular video card in this slot, but it will work at x4 speed. Besides that, this third slot does not offer support for SLI or CrossFireX arrays. Remember the SLI support on P55 motherboards will depend if the manufacturer has licensed this technology with NVIDIA and, so, not all motherboards based on Intel P55 chipset support SLI.

Gigabyte P55-UD6
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Figure 5: Slots.

Gigabyte P55-UD6 also offers two PCI Express x1 slots and two standard PCI slots.

Memory Support

Socket LGA1156 CPUs, as well as Intel socket LGA1366 and AMD processors, have an integrated memory controller. All other Intel CPUs use an external memory controller, located on the northbridge chip (also known as MCH, Memory Controller Hub) of the chipset. It means in this processors the chipset (better said, the motherboard) is the key component that says what technologies and how much memory you can install in your computer.

Since now the memory controller is inside the CPU, it is the processor, and not the chipset, that defines the memory technologies and the maximum amount of memory you can have. The motherboard, however, may have a limitation as to how much memory can be installed.

At the moment, the integrated memory controller of socket LGA1156 processors supports only DDR3 memories up to 1,333 MHz under dual-channel architecture, however Gigabyte says P55-UD6 supports DDR3 memories up to 2600 MHz through overclocking. P55-UD6 has six DDR3 sockets (which is commonly seen only in socket LGA1366 motherboards) and the moment each DDR3 memory module can have up to 4 GB, but it supports up to 16 GB because it does not support six double side modules (i. e., modules with memory chips soldered in both sides), but only four double side modules or a combination of two double side modules and four single side modules (which have chips only in one side of the module).

In order to achieve the maximum performance you should install two, four or six memory modules to enable dual-channel architecture. When only two modules are used make sure to install them on the white sockets. If you install six modules, the ones installed on blue sockets must be single sided.

Gigabyte P55-UD6
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Figure 6: Memory modules. Install two, four or six modules for the best performance.

Near the memory sockets there is a big power button, which allows you to turn your computer on with no need to connect the motherboard to a case panel. It is a great feature when there is a small button to do this, and having a big one is almost a enthusiast dream.

On-Board Peripherals

Intel P55 chipset is a single-chip solution. The basic features provided by this chipset include six SATA-300 ports (RAID support is optional), no support for parallel ATA (PATA) ports, 14 USB 2.0 ports supporting port disable, embedded Gigabit Ethernet MAC (Medium Access Control) and eight x1 PCI Express lanes. P55 does not support parallel ATA (PATA) ports.

Gigabyte P55-UD6, however, has twelve SATA-300 ports and one ATA-133 port. Ten SATA ports are internal and two are e-SATA-300 available on the rear panel of the motherboard. The six blue ports shown in Figure 7 are controlled by the chipset, and support RAID 0, 1, 5 and 10 (Intel Matrix Storage).Two white ports are controlled by a chip called by the manufacturer "Gigabyte SATA2 chip" (actually a renamed JMicron HMB363), which also controls the ATA-133 port, supporting up to IDE devices. This chip supports RAID 0,1 or JBOD. There are also two JMB362 chips, one controlling more two SATA-300 internal ports and other controlling the e-SATA ports on the rear panel. Each one of them supports RAID 0, 1 or JBOD.

This motherboard comes with an adapter that allows you to turn two internal SATA ports into more two e-SATA ports.

The ten SATA-300 connectors are placed facing the motherboard edge while the others are placed near the left edge of the motherboard, as you can see in Figure 7. This is a terrific solution, because on motherboards where the ports are facing up the video cards usually block the access to them or even completely prevent you from installing SATA cables on them. The heatsink that seems to cool the southbridge actually cools the additional SATA ports controller chips, since Intel P55 chipset does not have a southbridge.

Gigabyte P55-UD6
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Figure 7: SATA Ports.

This motherboard has a diskette port, controlled by an ITE IT8729 chip.

Gigabyte P55-UD6 offers the 14 USB 2.0 ports supported by the chipset, ten soldered on the rear panel and four available in internal headers. An interesting detail is the fact that two rear connectors are combo ones: the work as e-SATA ports or as USB ports. So, if you do not use those e-SATA ports, you will have ten USB ports on the rear panel, but if you use both the e-SATA ports, "only" eight USB ports will be available on this panel.

This motherboard comes with a FireWire (IEEE 1394) controller with three FireWire ports, two soldered on the rear panel (one standard and one micro tipe) and one available in an internal header.

The audio section of the motherboard is 7.1, produced by south bridge chip with the aid of a Realtek ALC889A codec, one of the best available, with a signal/noise ratio of 108 dB for analog outputs and 104 dB at its analog inputs, so you can use this motherboard to work profissionally with audio and video edition with no need for a separated sound card. The motherboard provides independent analog audio outputs in 7.1 format, which is excellent. It also has coaxial and optical SPDIF outputs on rear panel.

This motherboard has two Gigabit Ethernet ports controlled by two Realtek RTL8111D chips, which are connected to the system using PCI Express lanes and therefore are able to achieve its maximum performance. Those ports are compatible with "teaming" configuration, where both the ports are used as one in order to double the connection speed.

In Figure 8, you can see the rear panel of the motherboard: one PS/2 connector for keyboard or mouse (if you use it for a keyboard, you will need to use an USB mouse and vice versa), ten USB 2.0 ports (two of them shared with e-SATA ports), SPDIF coaxial and optical outputs, two FireWire ports, two Gigabit Ethernet ports and independent 7.1 analog audio outputs.

Gigabyte P55-UD6
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Figure 8: Rear panel.

Gigabyte P55-UD6 has a legacy serial ports, available through an internal header, but the motherboard does not come with the connector necessary to use it.

Other Features

Gigabyte P55-UD6 comes with other important features. All electrolytic capacitors used on this motherboard are solid from a Japanese manufacturer, which avoids the infamous leakage problem. The CPU voltage regulator circuit is equipped with ferrite chokes, which offer 25% less energy loss compared to iron shokes, and MOSFET transistors with low RDS(on) (low current leakage), that consume less energy and generate less heat. Furthermore, this circuit uses a 24-phase design, which is awesome. For a better understanding of the importance of such design, read our Everything You Need to Know About the Motherboard Voltage Regulator Circuit tutorial.

Besides that, the copper power lanes on the mother board are, accorging to Gigabyte, twice as thick as the found on other motherboard (this feature is called "2 oz copper"), which means less energy loss (and less heat dissipation), and more stable power for the components.

Gigabyte P55-UD6
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Figure 9: Top-shelf voltage regulator circuit.

In Figure 10 we can see other amazing features: a reset and a clear cmos buttons, which are very useful if you are searching for an extreme overclock. There is also a two-digit display that shows an error code if the initialization fails, allowing an easy problem identification.

Gigabyte P55-UD6
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Figure 10: Error code display.

In Figure 12, you can see the accessory set that come with P55-UD6.

Gigabyte P55-UD6
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Figure 11: Accessory set.

Main Specifications

Gigabyte P55-UD6 motherboard main features are:

* Researched at on the day we published this First Look article.


Gigabyte P55-UD6 is an excellent top shelf motherboard for the socket LGA1156 platform. Its strong points include the presence of twelve SATA-300 ports (with two eSATA ports), six memory sockets, support to SLI and CrossFireX modes, 24-phase voltage regulator circuit, heatpipe cooling for the regulator transistors and a high quality audio codec. And there is also the nice box, which surely will draw the attention on any shelf.

An amazing detail is the presence of two "combo" ports on rear panel: those ports can be used either as eSATA or as USB ports, feature that we had not seen in other boards yet.

It is a little less expensive than ASUS P7P55D Premium, but its price is away from the regular user budget reality anyway. But to be honest like P7P55D Premium this motherboard is not a board targeted to the average user.

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