Overclocking Experiments

Until this day Asus mainboards on iP965 chipset were considered the best platform for Intel Core 2 Duo and Intel Core 2 Extreme overclocking. Only with these boards you could hit the highest overclocking results without any too sophisticated manipulations. So, we would certainly expect Asus P5K Deluxe to be a highly overclocking friendly solution as well. Especially, since there are a few reasons for that: BIOS Setup with rich set of options for overclocking and official support of 1333MHz bus.

For our tests we assembled a system on our mainboard with Intel Core 2 Extreme X6800 processor. Besides we also used 2GB of Corsair Dominator TWIN2X2048-10000C5D DDR2 SDRAM, OCZ GeForce 8800 GTX graphics card, Western Digital Raptor WD1500AHFD HDD and SilverStone SST-ST85ZF PSU. Thanks to the memory that can run at up to 1250MHz frequency, we didn’t have to worry about its overclocking potential when clocking it synchronously with the FSB bus and setting the timings to 5-5-5-15. Processor was cooled with Zalman CNPS-9700LED cooler. We didn’t install any additional fans on top of the North Bridge heatsink, because it didn’t warm up too much, even during overclocking. The processor stability during overclocking was checked with the well-known SP2004/ORTHOS utility based on Prime95 code. We also used S&M program to check memory stability during overclocking.

We will not bore you with the detailed description of our overclocking experiments, especially since there is not much to describe. We managed to find the maximum bus frequency when the system remained stable pretty quickly. This was easy mostly due to simple overclocking procedure on Asus P5K Deluxe. Although there are a lot of settings that can be adjusted for maximum overclocking success, most of them can be left untouched.

For example, to achieve the maximum FSB frequency when our processor could work stably and reliably (it equaled 505MHz), we only had to increase the processor Vcore and raise the Vmem a little bit. Other voltages were set at their minimums, however it was more than enough for stable system performance.

While we were working on this and previous article, our lab received a new Intel Core 2 Duo E6850 processor with 1333MHz bus based on the new G0 core stepping. Overclockers are a little bit concerned about this core stepping, because the CPUs built on it should have relatively low frequency multipliers and hence their overclocking potential may be limited by the mainboard’s ability to raise the FSB speed. Of course, we couldn’t resist the temptation to check out the overclocking potential of Asus P5K Deluxe with a processor like that. For our overclocking experiments we reduced the processor frequency multiplier to 7x and pushed its Vcore to 1.45V. The results are provided on the screenshots below:

It proved a smart idea to reduce the processor clock frequency multiplier. Asus P5K Deluxe mainboard worked perfectly stable at 540MHz FSB, which is just another piece of evidence that this solution boasts truly excellent overclocking potential. By the way, we didn’t have to touch the chipset voltage at all to hit this frequency.

So, Asus P5K Deluxe is a great choice for overclocking of any processors, with low as well as high frequency multipliers. The board retains stability at up to 540MHz FSB (and maybe even higher), and these superior results are achieved with minimal efforts, without going though the whole bunch of finest settings, without any voltmodding or additional cooling on the chipset and the CPU voltage regulator circuitry.

At the same time we decided to check out the ability of our Asus P5K Deluxe mainboard to overclock memory. The thing is that mainboards based on previous generation Intel chipsets didn’t cope with DDR2 SDRAM overclocking as well as the solutions based on Nvidia core logic sets. Unfortunately, our tests showed that Intel P35 didn’t improve the situation that much. Once you’ve hit 1200MHz frequency on the memory bus, further overclocking is a real pain, independent of the selected timings or other settings. We managed to get our Corsair Dominator TWIN2X2048-10000C5D test kit to work only at 1213MHz in Asus P5K Deluxe mainboard, while in NVIDIA nForce 680i SLI based platforms it ran just fine at 1250MHz and higher.

However, I can hardly complain about this memory bus frequency being not high enough. Although Asus P5K Deluxe loses to some selected solutions when it comes to maximum memory bus speeds, its potential is more than enough for most overclocker DDR2 SDRAM kits out there, with very few exceptions.