BIOS and Overclocking
Being a budget based board, we weren't holding any hopes for a great deal of overclocking options, however, we were greatly surprised to find that EPoX is supporting overclockers even on the Sempron level of the K8 architecture.
The standard blue AWARD BIOS 6.0 is used to power the basic functions of the board. Once in BIOS you are greeted with a very standard and familiar setup. EPoX places its overclocking features under the "Power BIOS Feature" menu. From here all the overclocking options can be selected to the user's desire.
First off there is no auto overclocking on the EPoX 8NPA SLI. This is something we would like to see EPoX introduce, as auto clocking as we like to call it is now starting to take off as a viable alternative to manually setting the overclock parameters.
First on the list is the CPU frequency. Contrary to popular belief, AMD K8 CPU's "DO" have a front side bus, this is what the CPU die uses to connect to the memory controller built onto the CPU die with. This frequency is a standard 200MHz across the board, from there, the LDT or Hypertransport multiplier is used in order to get the link speed from the CPU to the external Northbridge. On the EPoX board, you can change the internal FSB frequency from 200MHz up to a maximum of 450MHz in 1MHz increments. While the end speed is simply not possible with today's CPU's, it's nice to see a wide selection provided.
Next frequency adjustable setting is the PCIE clock. This gives you control of the PCI Express frequency. Settings range from 100MHz up to a max of 145MHz in 1MHz increments. For best stability, leave the PCIE clock at 100MHz, as PCI Express buses are extremely sensitive to speed changes, even 110MHz causes system crashes, a great feature to lock this EPoX has done.
Next is the CPU Ratio control. AMD allows you to change your multiplier from your CPU default to a lower setting. You can't go up (only Athlon FX can do this) but you can lower the multiplier in order to raise the FSB without increasing CPU clock to insane and impossible clock speeds.
Now we get to voltage settings, the all important part of the Overclocking setup.
CPU voltage can be adjusted from the CPU default up to a maximum of 0.025v above standard in 0.005v increments. Next comes the DIMM voltage, and EPoX has given a good range here. DIMM voltage ranges from 2.5v up to 3.2v in 0.1v increments. This is an extremely generous range. Finally is the chipset voltage which can be adjusted from 1.5v up to a max of 1.8v in 0.1v increments.
With all these settings using our AMD Sempron 64 3000+, we managed to clock the CPU to a maximum of 2.12Ghz with CPU voltage at max, memory voltage at 2.9v, LDT link speed at 3x. Overall this was a good clock from 1.8GHz to 2.1GHz; however, using a budget CPU does limit ones overclocking ability.