In the late 90’s Abit practically invented overclocking and then perfected it with the first BIOS that offered overclocking without the need for physical jumpers on the motherboard. Since then, of course, other board manufacturers like Asus, DFI and Epox have adopted the same principles and the overclocking BIOS has become a standard on most enthusiast motherboards. What does the Abit AN8 32X board bring to the table compared to other NF4 SLI X16 options?
In our OC Guru menu in the BIOS we find most of the good overclocking options, like the multiplier adjustments seen here. The AN8 32X can set the multipliers from 4x to 25x, but you can only increase the multiplier on the FX processors. The other X2 and Athlon 64 CPUs are limited to decreasing the multiplier.
The external clock is the internal system bus that the Athlon 64 processors use to achieve their total clock speed. Here you can see that Abit defaults to 202 MHz, a slight cheat in the grand scheme of things, though the range for the bus is 200 to 400 MHz in 1 MHz increments.
The PCI Express bus can be changed as well with speeds up to 145 MHz.
The CPU voltage can be adjusted as well with options over the default settings up to 1.75v. That really isn’t very high, but helps keep users from applying too much voltage to their parts and potentially damaging it.
The memory voltages can be adjusted up to 3.2v which should be enough for some serious overclocking on most DIMMs.
This BIOS adjustment allows for more memory voltage tweaking by changing the starting voltage from which the previous BIOS setting is based on. Basically, you can add up to 60 mV extra to the power on the DIMMs.
Diving into other parts of the BIOS, we find the HyperTransport options for both the processor and chipset to chipset communication. Interestingly, despite NVIDIA’s insistence that this doesn’t happen, the north bridge to south bridge communications are set at a 4x HT multiplier, not the 5x that indicates the top speed. My recent look at how the HT speed affected SLI performance proved that this isn’t an issue for real-world performance, though it is interesting to note none the less.
In the memory configuration menu, you can adjust the ratio by which the memory speed is determined based on the CPU internal bus frequency. Here, the DDR400 option is default and represents a 1:1 ration of AMD’s bus to the memory bus. The DDR500 option would then represent the ability to run memory at 500 MHz while keeping the internal CPU bus at 400 MHz DDR (or 200 MHz standard). If you are trying to overclocking the HT bus on the processor, then lower this to DDR333 or below can help keep memory at a comfortable speed while just overclocking the processor.
This screen shows the lowest memory settings that Abit AN8 32X BIOS offers for memory timing tweaks.
Heading back into the first menu, we see the Abit EQ menu that allows us detailed control over the fans and warnings based on temperatures and fan speeds at various locations. Here we have the menu that allows you to set shutdown and warning beep temperature levels in case something goes wrong with your cooling or overclocking trial.
For the CPU, Abit gives you the options of 76 degrees Celsius to 95 degrees.
The system temperature ranges are 68 to 80 degrees.
Finally, the third temperature settings, based around the MOSFETs, can range from 81 to 130 degrees.
Voltage monitoring is very robust on this BIOS as well as you can see above. You can enable shutdowns and beeping warnings for everything from the ATX 12V rails to the DDR voltages.
Here in the fan speed monitoring section you can set shutdown and warning speeds for your fans connected to the various headers on the motherboard.
Each fan can even be controlled down to the amount of power sent to it (and thus the speed of the fan) based on the temperature settings that you decide. The control is pretty detailed allowing you to set a reference temperature in order to point it at the correct fan header and set highs and lows for both the temperature and fan speeds.
Overall, the BIOS on the Abit AN8 32X is very intricate, offers a good amount of overclocking options and by far the best control over the fan speeds and temperature monitoring we have ever seen.