ECS KN3 SLI2 Extreme has some overclocking options found under “Advanced Chipset Features” and “Frequency/Voltage Control”. You will find the following options (1.1C BIOS):

• Base clock (HTT clock): Can be adjusted from 200 to 210 MHz in 0.5 MHz steps and from 210 MHz to 300 MHz in 1 MHz steps.
• CPU voltage (“NPT Vid Control”): auto or from 1.200 V to 1.350 V in 0.025 V steps.
• Memory voltage: 1.80 V, 2.00 V, 2.05 V, 2.10 V or 2.20 V.
• North bridge voltage: 1.200 V to 1.350 V in 0.050 V steps.
• South bridge voltage: 1.500 V to 1.650 V in 0.050 V steps.
• CPU to north bridge HyperTransport voltage: 1.200 V to 1.350 V in 0.050 V steps.
• CPU ratio (“NPT Fid Control”).

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Figure 11: Overclocking options on ECS KN3 SLI2 Extreme (BIOS v 1.1C).

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Figure 12: Overclocking options on ECS KN3 SLI2 Extreme (BIOS v 1.1C).

You can also find detailed memory adjustments, where serious tweakers will have lots of fun.

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Figure 13: Memory adjustments on ECS KN3 SLI2 Extreme (BIOS v 1.1C).

Even though this motherboard at a first glance has several overclocking options, there is one big problem. There is only one clock generator. This means that when you increase the main clock generator, you will not only increase the CPU clock but also the PCI Express, the PCI and the SATA clocks. This is a major drawback for serious overclockers.

That is probably the reason we achieved a very low overclocking with this motherboard: we could set the base clock only up to 210 MHz, making our Athlon 64 X2 5000+ (which runs by default at 2.6 GHz) to run internally at 2.73 GHz, a just 5% increase on the CPU internal clock rate. Above that the system was unstable.

With all other high-end socket AM2 motherboards we reviewed to date we could make the system to run at least with a 220 MHz base clock.