When it comes to memory modules, there is usually a trade-off between performance and capacity. But the new MCR DIMM concept introduced by SK hynix and Intel on Thursday promises to combine extreme performance and capacity. The memory maker promises that his MCR DIMMs will enable data transfer speeds in excess of 8000 MT/s while offering unprecedented capacities.
SK hynix’s Multiplexer Combined Ranks (MCR) DIMMs are dual-rank memory modules that use a special buffer to allow both ranks to function simultaneously. Usually a module with 2 physical ranks he acts like one module, so if the host CPU (or memory controller) fetches data from such a module, it can only fetch 64 bytes of data at a time . However, buffers developed by SK hynix, Intel, and Renesas allow two physical ranks to work in parallel like two modules, so retrieving 128 bytes of data simultaneously from both ranks reduces the performance to 2. double.
The magic of MCR technology is that both physical ranks (memory chips) of a dual-rank module continue to run more or less at the “standard” clock. This simplifies the construction of high-capacity modules. Meanwhile, it is the Renesas multiplexer buffer that fetches 128 bytes of data from two modules and runs at over 8000 MT/s data transfer rate with the host CPU memory controller, simplifying the construction of high speed modules.
All buffers increase latency and tend to consume power, so these must be addressed at both the system and module level. On the other hand, in order for MCR DIMMs to work smoothly, the host CPU needs to support the technology. So it’s impossible to throw MCR DIMMs into existing machines in the hope of getting higher performance and higher capacity.
Sungsoo Ryu, Head of DRAM Product Planning at SK hynix, said:
Intel has said that future Xeon processors will support MCR DIMMs, but has not revealed which CPUs will support the technology and when. The company has reportedly been working on the technology for some time.
Dimitrios Ziakas, Vice President of Memory and IO Technologies, Intel, said: We look forward to bringing this technology to future Intel Xeon processors to support industry-wide standardization and multi-generational development efforts. ”
For now, MCR DIMMs are primarily a concept technology. SK hynix has confirmed that the company’s MCR DIMMs will “operate at a minimum data rate of 8 GT/s”. SK hynix has plans to bring the product to market, but has not disclosed when this will be. Given that DRAM manufacturers do not disclose timeframes, it is difficult to predict the capacity of MCR DIMMs. But perhaps he’s talking about 1TB-2TB modules, bearing in mind the capabilities of DDR5 SDRAM and the fact that MCR DIMMs are likely at least a few years away.