Buffered and Registered DIMMs: What\'s the Difference?
Whether or not your computer uses buffered or registered 168-pin DIMMs depends on its memory controller design. Some memory controller designs rely on the module to drive its own memory control signals. When the drivers (also referred to as buffers) are physically located on the module, you have a \"buffered module.\"
In registered applications, the drivers/buffers are incorporated into the memory controller design, typically located on the motherboard. In this type of application, the memory control circuitry located on the motherboard is capable of driving the memory control signals for all devices plugged into the memory expansion bus. In this case, you would use a registered module (i.e., a module that does not include its own buffers/drivers).
If you are wondering which is better, buffered or registered, it depends on your system requirements. It is strictly a matter of design. You can\'t use buffered modules in a memory application designed for registered modules and you can\'t use registered modules in an application designed for buffered modules. In fact, buffered and registered 168-pin modules are keyed differently to prevent them from being plugged into non-compatible configurations.
The following graphic will assist you in identifying a buffered versus a registered DIMM:
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