The chipset North Bridge is located at 45-degree angle to the processor socket. As a result, ASUS managed to lay out signal lines for both memory channels and processor in the 4-layer PCB. The North Bridge is equipped with a passive heatsink. Although many mainboard manufacturers provide the North Bridge of their i865PE based solutions with an active cooler, passive cooling is more than enough for it, too. This chip doesn’t heat up that much. Besides, throughout our entire test session ASUS P4P800 proved highly stable with its passive heatsink in the nominal as well as in the overclocked mode. The thing is that Intel manufactures its new chipsets with 0.25micron technology that is why the new i865PE dissipates max. 10W of heat.

Unlike the previous generation ASUS mainboards, the processor voltage regulator of ASUS P4P800 is designed as a three-channel circuit. We should note that ASUS gave up the EZ-plug, so now you need a fully-fledged ATX 2.03 power supply unit with a separate 12V 4-pin power cable.

To tell the truth, we were a bit disappointed with the DIMM slots voltage regulator circuit. For some reason ASUS used a linear circuit instead of the impulse one. Nevertheless, we tested the board under maximum workload with all the four DDR400 SDRAM modules installed and we didn’t reveal any stability issues.

One more thing worth mentioning. ASUS P4P800 Deluxe is equipped with a special technology protecting the AGP slot against the use of outdated 3.3V graphics cards, which are not supported by i865PE chipset and can cause fatal mainboard breakdown in no time. There is a special circuit, which won’t power up the board and will light up a LED signaling that a not supported graphics card has been installed. However, the P4P800 mainboard we reviewed today didn’t have a system like that. There is only one LED onboard indicating that the power is on or off.

BIOS and Overclocking

ASUS has been using Award Medallion BIOS in its mainboards for years. But this time, the company broke the old traditions. Instead of Award BIOS, ASUS P4P800 features BIOS from AMI. ASUS engineers explained that the new AMI BIOS core had become so convenient that they find it much easier to work with AMI from now on. But even though there is a completely new BIOS in ASUS P4P800 now, the Setup structure has been made as close to that of Award Medallion BIOS, as possible. Therefore, I assume ASUS fans shouldn’t have any problems using the new BIOS Setup.

Traditionally ASUS paid a lot of attention to overclocking friendly features of its boards. P4P800 is no exception: the Setup is very rich in options for successful overclocking.  All of them are available on JumperFree Configuration page:

With the launching of new mainboards based on i865 and i875 chipsets, ASUS announced the implementation of new AI Overclocking technology, which allowed speeding the system up to 30% (depending on the CPU and memory used) without much effort. To do this you should select the option called “Overclock 5% ... Overclock 30%”, which simply increases the FSB frequency by a certain value.