For our overclocking tests we used an Athlon 64 3500+ (2.2 GHz) with 512 KB L2 memory cache based on Venice core, which has a better overclocking capability than our Athlon 64 3800+ used on our benchmarking.

MSI K8N Diamond Plus BIOS V.1.12 overclocking options:

• External frequency: can be adjusted from 200 to 450 MHz in 1 MHz steps.
• PCI Express frequency: can be adjusted from 100 to 148 MHz in 1 MHz steps.
• Clock multiplier: Can be set from 5x to 19x in 1x steps. 
• HTT bus multiplier: Can be set from 1x to 5x in 1x steps.
• CPU voltage: from 0.80 V to 1.75 V and an extra overvoltage configuration of up to +0.75 V at 0.05 V steps.
• Memory voltage: With the memory voltage jumper on its normal position (see Figure 15) you can adjust the memory voltage from 2.60 V to 3.20 V at 0.10 V steps and with the jumper on “boost” position you can increase the memory voltage up to 4.1 V.
• Chipset voltage: Can be set from 1.2 V to 1.5 V. 
• PCI Express voltage: Can be set from 1.5 V to 1.85 V. 
• Dynamic overclocking: from 1% to 15% for the CPU and video cards based on nVidia chips.

K8N Diamond Plus has good overclocking settings, especially the memory voltage configuration, which can reach up to 4.1 V – value we don’t recommend even in a very aggressive overclocking due to the risk of drastically reducing the life span of your memory modules or even burning them.
Figure 15: CoreCell chip and jumpers set for increasing the memory voltage.

One particularity of socket 939 motherboards based on nForce 4 SLI X16 motherboards is the presence of two HyperTransport busses. When performing overclocking with motherboards based on this chipset you must control the frequency of both HyperTransport busses in order to prevent them from going over 1 GHz (Figure 16).

On Figures 16 to 21 you can check the several overclocking options provided by this motherboard.

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Figure 16: HyperTransport busses frequencies.

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Figure 17: Several overclocking options.

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Figure 18: More overclocking options.

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Figure 19: Complete memory timings settings.

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Figure 20: More memory timings settings.

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Figure 21: Dynamic overclocking

MSI added a switch on the motherboard for clearing the contents of the CMOS memory without the need of changing the position of a jumper, making it easier to clear the CMOS when you are setting your overclocking.

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Figure 22: Switch to clear the CMOS memory.

On Figures 23 and 24 you can check the overclocking we could achieve with this motherboard. On Figure 23 we could put HTT clock at 300 MHz and on Figure 24 we could put our CPU running at 2,798 MHz (279 MHz x 10).

Figure 23: HTT configured at 300 MHz.

Figure 24: Our 2.2 GHz CPU running at 2,798 MHz (279 MHz x 10).

With K8N Diamond Plus we could put our CPU running stable at 2,798 MHz (279 MHz x 10), an increase of 27.18% on its internal clock rate, an excellent result. To achieve this overclocking we had to change the HyperTransport bus multiplier to 3x, the memory voltage to 2.80 V, the CPU voltage to 1.5 V and keeping the memory clock always below 250 MHz.