Traditional DRAM technologies – DDR2, DDR3, DDR4 – have long been the workhorse memory of choice for embedded and personal computing. Even in higher performance enterprise and supercomputing applications, DDR4 still finds a place in the world.
However that time may be short lived.
With network speeds topping 100Gbps, a next generation memory architecture is required to meet efficiency and performance gains need in data packet processing, data packet buffering and storage applications. Higher performance processing (CPUs, CPUs, and FPGAs) and higher bit-count systems require memories with lower power budgets and lower system costs.
What is the future of memory?
According to Micron, it is their groundbreaking Hybrid Memory Cube (HMC). HMC is the first commercially available 3D memory architecture. It combines a logic layer connected by through-silicon vias (TSV) to four discrete parallel DRAM die. The logic layer internal to HMC simplifies the interface between the DRAM die and the system processing unit – whether a FPGA, CPU or GPU.
Instead of parallel interface similar to DRAM, HMC runs over high speed serial transceivers running up to 15Gbps. This approach provides system speeds of up to 160GBps.
In addition to increased bandwidths, HMC offers reduced power, fewer pins, and smaller footprints compared to traditional discrete DDR2/3/4 solutions. To date, HMC has been adopted by more than 100 members of the Hybrid Memory Cube Consortium. If you’d like to learn more about the basics of HMC, here are some additional resources:
- Micron’s HMC Product Page
- About Hybrid Memory Cube
- Avnet’s X-Fest 2014 Course: UltraScale™ Memory Interfaces
Increasingly, system reference designs featuring HMC are popping up. As mentioned in a recent Samtec blog, HiTech Global’s new Xilinx® Kintex® UltraScale™ Half Size PCIe Express Development Platform uses a Samtec Z-Ray®micro array interposer as the expansion connector for high-speed mezzanine cards. One of the expansions cards HiTech Global has developed is an HMC Module.
One major reason Samtec’s Z-Ray®solution was chosen was to allow for easy stacking of HMC modules on top of each other. This allows engineers evaluating HMC to increase the density of system HMC by stacking multiple HMC modules on top of each other. Z-Ray® has been designed with stacking in mind. Please look at the Z-Ray® Compression Hardware e-brochure for more details.
Z-Ray® can also support high performance data rates of up to 28 Gbps and beyond. When combined with its high density, flexible designs and low profiles, Z-Ray® is the preferable interconnect solution for any custom-designed HMC expansion card.
For more information on Samtec’s Z-Ray®Ultra Low Profile Interposers, please download the following resources: