There are a myriad of approaches, and each serves a unique purpose in optimizing performance and efficiency.

In the intricate world of modern chip architectures, the “memory wall” – the limitations posed by external DRAM accesses on performance and power consumption growing slower than the ability to compute data – has emerged as a pivotal challenge. Architects must strike a delicate balance between leveraging local data reuse and managing external memory accesses. While caches are critical for optimizing performance, the resulting coherency management requirements are potentially expensive. How is coherency used most appropriately? When is it required? Let’s dig in a little deeper.

Modern chip architectures are undoubtedly complex. In the recent discussion “AI Accelerator Architectures Poised For Big Changes,” I discussed what the industry calls the memory wall. External DRAM accesses limit performance and power consumption, so architects must balance local data reuse with external memory accesses. To visualize the effect of memory access better, I overlaid the memory access latencies from Joe Chang’s 2018 analysis with the timeline of a 1 GHz clock.

To read the full article on Semiconductor Engineering, click here.