The options for voltages management on Asus P5K Deluxe are also pretty impressive:

As we see, all voltages required for successful overclocking are there, which makes Asus P5K Deluxe a very attractive overclocker’s choice. Moreover, the supported ranges are broad enough for most cases, which is also an advantage.

One of the drawbacks we saw in previous generation Asus mainboards on iP965 chipset was the significant drop of processor voltage as a result of increasing CPU utilization and, logically, power consumption. Although such behavior of the processor voltage regulator doesn’t contradict Intel’s specifications, overclockers were pretty upset that the Vcore they set in the BIOS Setup was forced down. The new P5K Deluxe mainboard doesn’t suffer from this drawback anymore thanks to a special CPU Voltage Damper option. If you enable this option, the processor Vcore will not drop down more than by 0.032V (according to our measurements taken with Intel Core 2 Extreme X6800 processor overclocked to 3.2GHz). If the option is set to “Disabled”, the mainboard will act “typically”: the processor Vcore will drop down much more dramatically and may even hit the significant 0.08V.

All I have just said means that Asus P5K Deluxe boasts the most extensive overclocking-friendly features list possible. However, even if you are not into the whole overclocking thing, the everyday use of this mainboard in nominal mode will also hardly cause any trouble. Asus engineers also offer an alternative way of configuring this mainboard that doesn’t require adjusting all those settings. All options can be set to Auto, which will be a simple solution for inexperienced users. Moreover, the BIOS Setup of Asus P5K Deluxe also features automatic dynamic overclocking technology aka N.O.S. that offers the whole bund of preset profiles resulting in up to 30% increase of CPU performance.

The monitoring options offered by this mainboard are pretty standard. It can control two temperatures, rotation speeds of four fans out of six and four major voltages.

Note that the mainboard PCB thermal diode is located very close to MOSFET from the DDR2 SDRAM voltage regulator circuitry. As a result, the monitored temperature is actually much higher than it should be and doesn’t really represent the average mainboard PCB temperature.

The mainboard also features Q-Fan technology for fan rotation speed management of system case and processor fans depending on the temperature of the corresponding “hot spots”.

Another convenient tool that Asus engineers implemented in their new mainboard is the EZ Flash 2 utility built in the mainboard BIOS. It allows updating the BIOS from floppy disks and USB flash drives without even booting the OS.

Moreover, the board allows saving setting profiles in its own flash memory or on external storage devices. This way you can keep experimenting with settings without losing the most optimal achieved mode and also exchange user profiles with other Asus P5K Deluxe users.

In conclusion to our discussion of Asus P5K Deluxe BIOS features I would like to say that this mainboard deals very well with the situations when some parameters have been set incorrectly and the system cannot start. If the mainboard cannot pass POST because of the erroneous BIOS Setup settings, then it will reboot with default settings after system shut down and offer you to enter BIOS and fix the settings. In other words, you will hardly ever have to really use the Clear CMOS jumper.

So, from the theoretical standpoint, Asus P5K Deluxe provides overclockers with an excellent set of tools and options for successful CPU overclocking. However, we know a lot of situations when theory and practice are miles apart. Luckily, this is not the case for Asus P5K Deluxe mainboard. Our CPU overclocking experiments went on impeccably well. For example, we managed to hit the psychologically important 500MHz FSB without much trouble. We didn’t even have to raise the chipset voltage!

It is very important that that mainboard works absolutely stable at this FSB speed. By the way, Asus P5K Deluxe also works fine at lower FSB frequencies. We checked out the entire FSB frequency range between 266MHz and 500MHz and can confirm that the entire range is operational. So, we can definitely recommend this mainboard to overclockers.

0404 BIOS Update

Update: Today Asus engineers offer a newer BIOS version than the 0311 we used. The new BIOS version is marked as 0404 and was released on June 21, 2007. However, it is still a beta that is why we didn’t focus on it in this article. Nevertheless, we have to point out two very important things about it.

First, BIOS version 0404 allows switching Strap frequency manually. There is a corresponding option that offers you a choice of Auto, 200MHz, 266MHz and 333MHz. Thanks to this function you can now get access to the entire range of supported memory frequency dividers independent of the set FSB frequency: all you need is to set the Strap to 333MHz.

Second, the new BIOS version boasts faster work with the memory subsystem. It is achieved thanks to slightly different set of secondary timings that the mainboard adjusts automatically. Unfortunately, this improvement has another side to it as well: the system gets less stable during DDR2 SDRAM overclocking. However, we hope that they will fix this in the upcoming “non-beta” BIOS versions.