PCB Design

The PCB of Asus P5K Deluxe mainboard is designed in a slightly unusual way. Just look at the layout scheme:

It is not only the too few micro-chips on the PCB. The main peculiarity is the location of the PCI Express x16 and DIMM slots that have been moved closer to the lower edge of the PCB. The free space at the top of the PCB was then taken by the power components. Unfortunately, this change not only increased the free area around the CPU.

Among the drawbacks of such PCB layout we would like to mention the inconvenient location of the HDD connectors. Parallel ATA ports had to be moved to the lower edge of the PCB, which may require the corresponding cable to run through the entire system case. Serial ATA ports appeared so close to the first PCI Express x16 slot that you may find it hard to connect any cables to them with the preinstalled graphics card. Clear CMOS jumper also appeared very inconveniently hidden beneath the cooling system of the installed graphics card, which may result in certain difficulties.

However, you will have to deal with all the above mentioned drawbacks only once: during system assembly. As far as the optimal thermal conditions inside the assembled system are concerned, it would be hard to find anything to complain about. Large free area around the processor socket and chipset North Bridge should improve the cooling of these “hot spots”.

So, at first glance Asus P5K Deluxe shouldn’t have any issues with large CPU cooling solutions. There are no large electronic components around the LGA775 socket that can prevent you from installing some massive coolers. However, there still may be some cooler compatibility issues. To understand what I am talking about, look at the reverse side of the Asus P5K Deluxe PCB:

As you can see there are some MOSFET from the processor voltage regulator circuitry. However, this is not the worst thing yet. We are much more concerned with the hanging contact pins of the electronic components soldered through the PCB as they may prevent you from mounting some of the backplates.

The processor voltage regulator on Asus P5K Deluxe is designed as an eight-channel circuitry. It uses solid-state electrolytic capacitors and ferrite core chokes. So, we have no doubts about highest reliability of the CPU voltage regulator here.

Thanks to up-to-date components and eight voltage regulator channels, the CPU voltage regulator dissipates not too much heat during work. Nevertheless, Asus equipped its P5K Deluxe with a two-part cooling system. The first half of this system is covered with a simple aluminum heatsink painted with “copper” color. I doubt that it is a highly efficient heatsink, as it has very weak retention and doesn’t get pressed tight enough to the MOSFET surface. The second half of the voltage regulator cooling system makes a mode solid impression: it is of neater design and sits tighter on top of the cooled elements. However, there are heatpipes running from this second heatsink to the heatsinks on the chipset North and South Bridges thus redistributing the heat over the system and warming up the MOSFET with the heat from the core logic components.

As for the chipset itself, its cooling system featuring heatpipe design performs quite well, even though it is made of “copper-colored” aluminum. Somewhat lower heat dissipation of the new Intel P35 chipset compared with the previous generation solutions is certainly one of the reasons for that. This could be why Asus decided not to include an additional chipset fan with the Asus P5K Deluxe mainboard and stuck to the passive cooling solution. However, you shouldn’t worry about Asus P5K Deluxe North Bridge overheating because from now on Intel integrates its thermal diode not only into CPUs but also into chipsets. Intel P35 North Bridge monitors its thermal performance and will shut down in case it hits dangerous temperatures.

The mainboard rear panel has also prepared us a small surprise: there is no PS/2 port for the mouse – there are two additional USB 2.0 ports instead, so now there are six of them total there. They retained the PS/2 keyboard port at this time. Besides, there is also an IEEE1394 port, two eSATA connectors, an optical and coaxial SPDIF Outs, six analog audio jacks, two network RJ45 ports with diagnostic LEDs and a WiFi antenna connector.

In addition to the rear panel ports and connectors that I have just mentioned, Asus P5K Deluxe also features four USB 2.0 ports, an IEEE1394 port and a Serial port laid out as pin-connectors on the PCB.