PC1066 Rambus RDRAM RIMM: 184 pin, 2.5 Volt
PC1066 memory is also backward compatible to work with PC800 systems.
RDRAM is developed from the traditional DRAM, but the architecture is completely new. It has been streamed and optimized to yield new performance.
The RAMBUS design gives a more intelligent access to the RAM, meaning that units can "prefetch" data and this way free the CPU some work. The idea is that data is read in small packets at a very high clock speed.
The RIMM modules are only 16 bit wide compared to the traditional 64 bit SDRAM DIMMs, but they work at a much higher clock frequency.
The Rambus modules work on 2.5 volts, which internally is reduced down to 0.5 volt when possible. This helps to reduce heat and radio signals.
The RIMMs hold controlling chips that turns off the power to sections not in use. They can also reduce the memory speed if thermal sensors report of overheating.
All RAM slots have to be full; this is new, with RAMBUS we have to fill in blank modules in slots which are not in use. The blank modules are called CRIMMs (with a 'C' for continuity).
The RIMM modules hold 184 pins.