Even as the industry ramps up for the initial launch of DDR5-based servers, it’s already time to look to the future. It illustrates the fact that the demand for memory bandwidth is insatiable. Advanced workloads running in the data center want all the bandwidth they can get and then some.
The first of the DDR5-based servers will hit the market with RDIMMs running at 4800 MT/s. This is a 33% increase in data rate over top-end 3200 MT/s DDR4 RDIMMs in current high-performance servers. DDR5 memory incorporates a number of innovations and a new DIMM architecture which enable that speed grade jump and support future scaling.
So let the scaling begin. Rambus has announced we are sampling the industry’s first 5600 MT/s DDR5 Registering Clock Driver (RCD) for the “next-next generation” of server main memory. The RCD is the conductor for the orchestra of DDR5 DRAM devices on the RDIMM. It provides the control plane Command and Address signals as well as the clock for synchronous operation. For a double data rate speed of 5600 MT/s, the RCD must provide a 2800 MHz clock.
As data and clock speeds increase, so too do the signal and power integrity (SI/PI) challenges. This gets even tougher given that DDR5 lowers the operating voltage to 1.1V to maintain the power envelope of the RDIMM. A lower voltage means lower design margin to achieve error-free operation.
Fortunately, Rambus has over 30 years of high-performance memory experience and is renowned for SI/PI expertise (we literally wrote the book). We leveraged this technology heritage to deliver another in a long line of industry firsts with this RCD product milestone. 5600 MT/s represents a further big jump in memory bandwidth, and with demands what they are, expect many more to come.