Parameters of Memory Overclocking. Part IV

Active to Precharge Delay (tRAS, DRAM RAS# Activate to Precharge, Min RAS# Active Time)

This parameter sets the minimal time between the line activation command and the closing command, i.e. the time when the line may be open.

A range adjustment depends on the motherboard model and may be from 1 to 63 cycles. There is no unambiguous dependency between the value of this parameter and memory productivity so you should select tRAS experimentally.

DRAM Command Rate (1T/2T Memory Timing)

This parameter sets the delay when the commands transfer from controller to memory.

Possible values:

  • 2T (2T Command) – the delay value is equal to two cycles that is consistent with the lower speed but with higher reliability of memory operation;
  • IT (IT Command) – the delay of one cycle increases the memory speed but not every system can operate in its normal mode then.

Some versions of BIOS have the “2T Command” parameter where the delay of two cycles is set after its turning on, and the delay of one cycle – after its turning off.

DDR/DDR2/DDR3 Voltage (DDR/DDR2/DDR3 OverVoltage Control, Memory Voltage)

This parameter increases the power supply voltage of memory chips for their more stable operation on higher frequencies. If you select the value “Auto (Default)” for memory chips, a standard power supply voltage will be set which is 2,5 W for DDR memory, 1,8 W – for DDR2 and 1,5 W – for DDR3.

You can increase the power supply voltage a bit more for more effective memory overclocking by choosing one of suggested values. The range and step adjustment depend on the motherboard model, and both absolute and relative values of voltages can be used as values.

Some motherboards may have additional parameters for setting nominal voltages separately for every memory channel, for example Ch-A/B Address/Data VRef. They almost always require setting the value Auto, and there may be need for their adjustment only under extreme overclocking.


To avoid permanent damage of memory modules, do not set too high voltage values and also take care about more effective cooling of modules.