Intel D875PBZ - Page 5

..:: D875PBZ “Bonanza” Layout: Northbridge Area ::..

The Intel i82875P Northbridge is covered by a very large aluminum heatsink with no available active cooling. In case you’re wondering the measurements of this unit, it measures 2 inches x 2 inches. This heatsink offers 175% of the typical i845PE heatsink contact surface area! In our tests, this heatsink did tend to get slightly warm, but it was nothing that this monstrosity of a heatsink couldn’t handle. The heatsink itself is equipped with an array of 144 vertical “pins” that are roughly 1.5 inches tall. The i82875P Northbridge is located in close proximity to the processor socket with the heatsink coming within around a quarter inch of the CPU retention mechanism. I think it is pretty obvious when I say that the area around the i82875P is very clear of any major items, solely due to the size of the heatsink. I doubt anyone will need any aftermarket Northbridge cooling with the D875PBZ, even though they’d be hard pressed to get the unit detached from the PCB.

Off to the left of the i82875P Northbridge we come across the system’s voltage regulation chip/s. For those interested, Intel is using an Analog Devices ADP3168 6-Bit Programmable 2-4 Phase Buck Controller. This BC allows selectable voltages ranging from 0.8375V to 1.6V, active current balancing on all output phases, and on-the-fly VID code changes. This area of the board is also home to the four-pin ATX 12V power connector, along with a third three-pin power connector for a rear system case fan and a 14.3MHz clock crystal.

..:: D875PBZ “Bonanza” Layout: Expansion Slots ::..

The next stop on our trip around the D875PBZ is of course, the expansion slot area. The expansion slot setup for our evaluation motherboard will do a nice job of pleasing enthusiasts with one AGP 8x slot, and the chipset maximum of five PCI slots. The AGP slot has a built in retention mechanism similar to those we have seen on other boards. When you mount your graphics card, it pushes a tab with a small plastic protrusion down that holds the graphics card in place. If you ever choose to remove the graphics card, you simply push down slightly on the tab to disengage it and remove the card. We’ll start off our trip towards the top with the AGP slot and work our way down to the bottom of the board as is the norm.

If you take a look below the rear I/O ports along the left hand edge of the motherboard, we come across the chip that we earlier spent a good deal of time going over, the 82547EI Gigabit Ethernet Controller. As we can also see, there is a 25.000MHz clock crystal positioned above the 82547EI Gigabit Ethernet Controller. One thing that many of you may notice is missing is the rear I/O ports for the onboard audio. According to Intel, at the present time, there will be no integrated audio on the D875PBZ for the retail market. The market for integrated audio will be for OEM’s and other system integrators unless a determination is made that the retail market wants integrated audio. The remaining area around the 82547EI Gigabit Ethernet Controller is extremely clean with only a few resistors being the largest items of note.

The remainder of the area around the PCI slots is clear of any other chips, or major headers of note. If we take a look along the edge of the board, we can see all of the screening for the various audio headers, components, and connectors. According to the design, the CD audio in header will be placed between PCI slots two and three, while the aux in header will be placed farther down the board towards PCI slots four and five. The audio codec itself is placed between slots three and four, while the front panel audio header is right next to the CD in header. I like the fact that this header is placed lower on the board than most designs, however I would prefer to see it slightly lower, more towards the bottom of the board for ease of cable routing if need be.