BIOS Overclocking

The CPU overclocking options are on the CPU Config page.


There are three overclocking modes to choose from. "Auto" runs the system at its default speed. When you are looking to do overclocking, please pick the "Async." mode. The other mode synchronizes PCI-E clock with CPU clock and so limits overclocking a lot. I don't see any reason why you would want to pick "Sync".


The CPU Frequency can be selected from 150 MHz to 400 MHz. 400 MHz is quite optimistic, but there is no artificial clock limit of 275 MHz like on the previous 939Dual board.


The PCI-Express clock should be left at 100 MHz. There are only very few applications that benefit from higher speeds here.


PCI clock can either be synchronized with the PCI-E clock or selected from several frequencies. It's usually best to leave it at 33.33 MHz.


There are no half multipliers available. The list shows a lot more multipliers than will actually work. With our CPU the maximum is x9.


As we know from other ASRock boards, the CPU voltage options are quite limited. The maximum here is 1.45V on A64 and 1.55V on A64-FX. We have a very simple voltmod to increase the voltages here.


On the chipset page you can configure several chipset related settings.


With this option you control the multiplier of the HTT bus. If you do some serious overclocking you should lower the multiplier here, so that the HTT stays in its spec of around 1000 MHz.


No idea what this option actually does. If I understand the description right it tunes something in the PCI-Express graphics port.


VCCM is some memory related voltage. I had to set it to ultra-high to get my BH-5 memory stable. It would help a lot if the options were labeled with values instead of unmeaningful text.


Same here. Auto is probably the same as normal.

Memory Timings

The memory timings section looks quite good. Sure, you don't have all the options like on the elite overclocker boards, but what you have should suffice for most users.


As memory dividers you can pick 133 MHz (3:2), 166 MHz (4:3), 200 MHz (1:1). There are no upward multipliers available.


If you have issues with memory stability, try enabling the flexibility mode. This may get your system running, at the cost of some memory performance.


This is the option to pick between 1T and 2T timing in the memory controller. 1T is better for performance, try that first.