The new versions of the BIOS Setup of ABIT KV8-MAX3 allow saving settings profiles either in CMOS or in flash memory. Thus, you can easily restore all BIOS settings after clearing up the CMOS data. The mainboard can store as many as five profiles; it is something like the CMOS Reloaded technology from DFI.

The BIOS Setup has some tricky places, too. For example, when you select default processor settings, the mainboard deliberately sets the FSB frequency to 204MHz (2% above the nominal). Of course, ABIT KV8-MAX3 will perform faster in benchmarks, but this is indisputable overclocking.

Let’s find out how well will ABIT KV8-MAX3 run after overclocking. As I have mentioned earlier, VIA K8T800 chipset behaves badly at overclocking, since it cannot lock the frequencies of the AGP and PCI busses at the nominal values. On the other hand, all currently available models of the Athlon 64 processors do not allow increasing the frequency that much with simple air cooling. In fact, 20% frequency gain is the maximum you can get today (until the new revision of the core – CG). Under such conditions, the growth of the AGP and PCI frequencies along with the FSB clock-rate may not be a crucial factor. So let’s turn to practical tests.

The frequency of Athlon 64 processor is calculated by multiplying the CPU multiplier by the processor bus frequency. You should be aware, though, that the frequency of the processor bus is a formal thing in Athlon 64 systems: it is merely the frequency of the signal for clocking the CPU and other system components. Athlon 64 connects to the chipset via the special two-way HyperTransport bus with a width of 16bits and 800MHz frequency (processor bus frequency times 4, to be exact). As for the memory frequency, it depends on the processor frequency, since the memory controller is integrated into the CPU. VIA K8T800 chipset clocks the AGP bus at 1/3 of the CPU bus frequency. It means that when you increase the processor bus frequency in the BIOS Setup, you automatically raise the frequencies of the CPU, memory, HyperTransport, AGP/PCI. It would be much better for overclocking, if we could speed up Athlon 64 by changing its multiplier. In this case, we would avoid potential pitfalls like reaching the frequency peak of the chipset or AGP/PCI devices rather than of the processor. However, this processor doesn’t allow increasing its multiplier above the nominal value. As for our particular mainboard, it doesn’t even know how to decrease the multiplier. So, we only have the option of overclocking the FSB here.

We took an Athlon 64 3200+ (2.0GHz) for our overclocking tests. The cooling system was pretty common: we used a cooler from the processor retail box. For better results, we also increased the CPU voltage by 10%, up to 1.65V. We also took special overclocker memory modules from OCZ, the PC4000 Gold Edition, that are guaranteed to work at frequencies up to 500MHz. By using such memory, we could keep the same memory frequency divisor (it was 1/10 of the CPU frequency throughout our tests or “DDR400” as the BIOS Setup calls it).

We had some problems at 222MHz FSB: namely the RAID array we used wouldn’t work any longer. It turned out the SerialATA RAID controller from VT8237 South Bridge (as well as the external Silicon Image Sil3114) is very sensitive to the PCI frequency. When the FSB clock-rate was equal to 222MHz, the PCI frequency reached only 37MHz, but that was enough for the SerialATA controller to lose its stability. We continued our overclocking using one Parallel ATA drive -Western Digital Caviar WD400JB. Fortunately, the Parallel ATA controller in the South Bridge is more stable during overclocking than its SerialATA counterpart.

With a single Parallel ATA drive, we reached higher results. The processor remained stable until the FSB frequency reached 232MHz. This is the maximum for our processor. Neither the reduced HyperTransport frequency nor higher memory divisors helped to improve the result any more. However, our experience with the Athlon 64 3200+ suggests that this CPU rarely conquers higher frequencies.

Thus, ABIT KV8-MAX3 can be used for overclocking the processor, but you should use Parallel ATA hard disk drives rather than SerialATA ones in this case. This limitation is caused by VIA K8T800 chipset, and there is no reason to blame the ABIT’s engineering team. This chipset doesn’t allow locking the AGP/PCI frequencies, and you will be better off choosing a mainboard on the NVIDIA nForce3 150 for overclocking (in spite of their lower performance) or on the SiS755 (if you are lucky to find one).