DFI LAN Party PRO875B - Page 4

..:: Layout: Northbridge Area ::..

The Intel i875P Northbridge is passively cooled by a fairly large aluminum heatsink unit. This unit is similar is looks that that which was utilized on the Soyo motherboard we reviewed previously. This heatsink is held down in the untraditional method of utilizing two metal hooks built into the PCB. This strategy of heatsink installation was utilized heavily back with the original i845 series of chipsets, and lately we have been seeing more manufacturers opt for the thermal pad / through-pin method of installation. Throughout testing, this heatsink rarely became more than lukewarm to the touch, so it does its job quite nicely. Upon removal of the unit, we found that as expected, a thermal pad was used between the chipset core and the heatsink. Both the i875P MCH and the heatsink are oriented on a forty-five degree angle to the bottom of the processor socket in order to shorten the traces.

If we take a look to the left of the Intel i875P Northbridge, we come across only a scattering of small IC’s and capacitors. Normally, this area would be home to several of the IC’s that directly deal with the core voltage power supply for the processor, although in this case this area only houses some minor electrical components, such as a voltage regulator, a single MOSFET, and several smaller capacitors. The setup is likely used to produce one of the many varying voltages needed to power the motherboard components. There are also a few resistors, and ceramic capacitors scattered through this area, which is very common around the Northbridge. The only remaining item in this portion of the motherboard is a lone 14.318MHz clock crystal, located to the left of the voltage regulator.

..:: Layout: Expansion Slot Area ::..

As usual, the next stop on our trek around the PRO875B’s PCB is the expansion slot portion of the motherboard. This area is typically one of the two major zones of the motherboard where, feature-wise, things can tend to become far more packed together, whether it is due to headers, controller chips, or other miscellaneous items dealing with the motherboard feature set. The AGP slot on the PRO875B is a bright orange color, which matches the remaining PCI slots as well. These will glow bright orange when placed under a UV light, and will produce a stunning effect. The PRO875B, of course, supports AGP 3.0 specifications otherwise known as AGP 8x. The slot features an interest locking mechanism, which for the life of me I can’t explain easily in words. Take a look at the image above, and you’ll get the gist of it.

The first items we come across are located beneath the rear I/O panel, and both address the PRO875B’s onboard LAN solution. The PRO875B utilizes the well known Intel Gigabit Ethernet Adapter, and also does indeed use the new CSA bus that is featured on the i875P and i865PE chipsets. For quite some time, manufacturers were pumping boards onto the market that failed to utilize this new bus, and were therefore clogging the PCI bus more than it needed to be with devices such as IEEE1394, and SATA. Now that the Gigabit Ethernet has been removed from the PCI bus, there is more “breathing room” for other devices to utilize the bus. If we take a look above the Ethernet Controller, we find a single 25.0MHz clock crystal.

The next major IC we come across is located directly alongside PCI slot number two, and that is the Winbond W83627HF-AW Super I/O chip. This chip is typically responsible for providing support for the older legacy devices for the system such as the serial ports, midi port, parallel port, and PS/2 keyboard and mouse ports. It also serves other functions such as support for floppy devices. It can also hold the responsibility for looking after the various systems critical measurements, such as the voltages, temperatures, and fan readings. Other than the W83627HF-AW chip, this portion of the board remains clear of any major items.

As we finish our trek around the expansion slot portion of the PCB, we next find the core components and connectors for the onboard audio solution. Starting from the top and working our way down, we first come across the Game/MIDI port header. As we saw with the package, since this connection couldn’t be included in the rear I/O panel, DFI chose to include an expansion bracket with a Game/MIDI port. Just below this header, we next find the typical white and black CD and Auxiliary audio connectors for CD-ROM’s, DVD-ROM’s, etc. The C-Media audio codec IC only a good quarter inch south of these two audio connections, while the front panel audio header and S/PDIF header run along the bottom edge of the board. This is where I would like to see the front panel audio header located on as many motherboards as possible. This positioning will allow for the cables being run from the front of the case to be guided along the bottom of the casing, thereby lessening the mess and improving airflow. Now, in some cases, when ports are located higher up on the case this positioning won’t work quite s well as the “typical” positioning would, hence why I don't make a big fuss about it.