Wiesław Wilk, CEO of Wilk Elektronik – the manufacturer and owner of the Goodram and IRDM brands – shares insights into server RAM modules and how to choose the right one.
Server RAM, or more precisely, server RAM modules, are products comprising many components. As with any DRAM module, its basic component is a PCB onto which integrated circuits and passive components, like resistors and capacitors, are soldered during the production process. The main difference between server RAM and consumer RAM is the quality and quantity of the chips. A server RAM needs to run 24 hours a day, so the chips used in the product must be of a high quality and carefully selected in pre-manufacturing.
There are different server RAM modules – ECC UDIMM modules (unbuffered ECC), registered RDIMM modules, and LRDIMM, or Load Reduced DIMM modules.
EEC UDIMM RAM modules feature an additional 8-bit chip for every 64 bits. In practical terms, each RAM module has nine memory chips, not eight. For a dual rank module, it is eighteen chips instead of sixteen. These extra ICs are not used for writing data. Their only function is to support the ECC (Error Correction Code) algorithm that detects and corrects errors in the RAM module.
RDIMM modules feature ECC and what is called the Register, which provides communication between the RAM module and the memory controller. The controller in the CPU communicates with the Register in the memory module, then the register manages how the RAM chips operate. As a result, RDIMM modules enjoy high RAM stability in multi-module systems, which allows it to operate with more modules on a single motherboard, as the Register takes the load off the memory controller.
The last type of RAM modules, LRDIMM, have data buffers to complement the Register. The CPU memory controller communicates with the Register and with separate buffers dedicated to each individual RAM chip. The RAM module control is managed by the Register while the buffers transfer data.