BIOS: Overclocking

Overclocking

The Overclocking Features page in the BIOS is home to the overclocking options. Sapphire has done an excellent job here, the options are well rounded, you might even find some options which no other board offered yet.


The CPU FSB can be changed in 1 MHz steps between 200 MHz and 440 MHz. Options for the PCI-Express bus frequency range from 100 MHz to 200 MHz. Most people fix it at 100 MHz and it works well.


Four values are available for Northbridge voltage. 1.50V sounds like a bit much to me, especially without active cooling on the chipset. But it's better to have the options than to be limited. ATI lists 1.26 V as maximum recommended Voltage for the chipset, but hardcore overclockers have never cared about manufacturer maximums, anyway.


The voltage of the HyperTransport link can be increased up to 1.5 V as well.


Two voltages of the PCI-Express bus can be changed.


Great job here again, Sapphire. DDR voltage is selectable from 2.5 V all the way up to 4.0 V in 0.05 V increments.


This setting allows you to define how much the VTT termination voltage should change from the default setting.


Unlike the Pentium 4, AMD's processors have a selectable multiplier (only downwards). This allows you to boost performance even more, if your memory can handle the speeds. The options here range from 4.0x up to the CPU maximum (in our case 9.0x). Half dividers are available as well.


The easiest way to get a few more MHz out of your CPU, is by increasing the Core voltage. Sapphire's motherboard is one of the few boards to allow undervolting. Minimum voltage is 0.825 V, in steps of 0.025 V you can go up to 1.550 V, which isn't that much for the more extreme people. From a hardware perspective the board can easily support over 2.0 VCore. The BIOS option for an "offset" voltage was not in this tested BIOS. A few days later we got a new one with the options, but they did not work. It was possible to change the offset voltage via software, so it's just a matter of time until Sapphire gets this working in the BIOS.

Memory Timings

The Sapphire PI-A9RX480 has a ton of memory timing options. Listing them all would take too long, take a look at the pictures and be impressed. There are three "sections": Timing Mode, User Config Mode and DRAM ECC Feature Control.
Good that there is an auto setting for each section, so newbies don't have to worry about getting every option right.


When setting DRAM Timing to manual you can change the standard timings Tcl, Tras, Trp and Trcd.


Another option is to set your memory divider to change the frequency your memory is running at. There are seven different settings which should cover most situations you would like to run your memory in.