The DDR2 1066 module, which comes in 2GB and 1 GB kits, is designed for extreme gamers who want to overclock their PCs until they are red hot piles of ash on their desktop.
Apacer's DDR2 1066 512MB memory module has been tuned to work best on Asus's P5B Deluxe motherboard with Intel P965 Express chipset. This means that the preset 1.8V is passed without needing to adjust the voltage. The DDR2 1066MHz 1GB only needed to be adjusted to 2.0V.
When you are playing with fire you need a better cooling system. According to the Apacer press release, the module uses an oversized, high-performance, extruded aluminium heat sink, which it thinks can do the job.
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