HBM, an abbreviation of High Bandwidth Memory, is a high-performance memory with a three-dimensional (3D) structure where DRAM (dynamic random access memory) are stacked on top of each other. The JEDEC (Joint Electron Device Engineering Council) adopted HBM as the industry standard in October 2013.

    HBM Architecture

    HBM uses a bi-directional wide-interface architecture that allows for very high memory bandwidth along with low power consumption. The vertically stacked structure of HBM dies provides several performance and power consumption advantages. The connection between the dies is done using TSV (through silicon via) technology that reduces the connectivity impedance and in turn power consumption.

    Each DRAM die is connected using 2 x 128-bit channels. Therefore, an HBM stack of 4 DRAM dice has a total of 8 channels which provides a total access width of 1024 bits. Each DRAM die can be accessed and clocked independently. Thus, each channel provides an independent memory array.

    Advantages and Importance of HBM

    HBM provides a solution to many computing problems due to its higher bandwidth, low power consumption, and smaller form factor. The applications of HBM include high-end gaming GPUs, high-performance servers, AI, high-performance computing, network devices, etc.

    The operating frequency of processors in the devices we use are increasing day by day, but the system performance is hindered due to limited memory bandwidth. Applications in AI (artificial intelligence) and other fields require fast matrix calculation. While other graphics-heavy applications needed substantially more bandwidth. HBM helps improve overall system performance by providing much more memory bandwidth compared to other types of memory.

    Additionally, the increasing bandwidth requirement also demanded more power from the memory making it a significant portion of a computer’s overall power requirement. This is where the low power consumption of HBM becomes extremely useful.

    And while DDR and GDDR provide good performance and low manufacturing costs, they also have limited bandwidth. HBM provides a higher bandwidth alternative while also requiring less power.

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