Originally Posted by fanboynz
Is that safe? Any downsides for having it that high?
DDR2 On-Die Termination (ODT) improves signal integrity by building dynamic resistive technology within the memory chip itself. This reduces the material and testing cost for motherboard manufacturers on top of other benefits. Unintended signals can bounce off from either active or passive components, but only active components like DRAMs are adversely affected. ODT negates the negative effects of signal echoes along the bus during read-write operations at the chip level.
Ironically, if the termination is too effective, it is possible the data signal can be absorbed when the memory timing is inaccurate – overclocking can sometimes result in this data truncation memory error.
The BIOS in some motherboards allows the user to manually adjust the resistive nature of ODT between 50, 75, 150 ohms. According to JEDEC specification, 50 ohms is a mandated for DDR2-667 and beyond on some platforms.