Intel Broadwell's EDRAM: The Predecessor to VCache

Intel Broadwell's EDRAM: The Predecessor to VCache

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Introduction

Intel's Broadwell microarchitecture introduced a unique feature known as Embedded DRAM (eDRAM), which served as a precursor to the more recent VCache technology. This innovation aimed to enhance performance by adding an additional cache layer between the CPU and main memory.

Details

The Broadwell processors, launched in 2014, featured up to 128 MB of eDRAM, which acted as an L4 cache. This eDRAM was built on Intel's 22nm process and was separate from the main CPU die, allowing for flexibility in production. The eDRAM provided lower latency and higher bandwidth compared to traditional main memory, improving overall system performance.

Performance and Features

The eDRAM cache significantly boosted performance in memory-intensive tasks and gaming. For example, the Broadwell i7-5775C processor, with its 128 MB eDRAM, outperformed many of its contemporaries in gaming benchmarks. The eDRAM cache helped reduce memory latency and improve data access speeds, making it a valuable addition to the CPU architecture.

Community Reaction

The introduction of eDRAM in Broadwell was well-received by the tech community, as it demonstrated Intel's commitment to improving performance through innovative cache solutions. However, the technology was eventually phased out in favor of newer advancements like VCache, which integrated the cache more closely with the CPU die.

Conclusion

Broadwell's eDRAM technology paved the way for future cache innovations, including VCache. While eDRAM is no longer used in modern processors, its impact on performance and the lessons learned from its implementation continue to influence CPU design today.