This article describes Memory Squeeze (MemSZ), a new approach for lossy general-purpose memory compression. MemSZ introduces a low latency, parallel design of the Squeeze (SZ) algorithm offering aggressive compression ratios, up to 16:1 in our implementation. Our compressor is placed between the memory controller and the cache hierarchy of a processor to reduce the memory traffic of applications that tolerate approximations in parts of their data. Thereby, the available off-chip bandwidth is utilized more efficiently improving system performance and energy efficiency. Two alternative multi-core variants of the MemSZ system are described. The first variant has a shared last-level cache (LLC) on the processor-die, which is modified to store both compressed and uncompressed data. The second has a 3D-stacked DRAM cache with larger cache lines that match the granularity of the compressed memory blocks and stores only uncompressed data. For applications that tolerate aggressive approximation in large fractions of their data, MemSZ reduces baseline memory traffic by up to 81%, execution time by up to 62%, and energy costs by up to 25% introducing up to 1.8% error to the application output. Compared to the current state-of-the-art lossy memory compression design, MemSZ improves the execution time, energy, and memory traffic by up to 15%, 9%, and 64%, respectively.

中文翻译：

---

内存空间

本文介绍了内存压缩 (MemSZ)，这是一种用于有损通用内存压缩的新方法。MemSZ 引入了 Squeeze (SZ) 算法的低延迟并行设计，可提供激进的压缩比，在我们的实现中高达 16:1。我们的压缩器放置在内存控制器和处理器的缓存层次结构之间，以减少允许部分数据近似的应用程序的内存流量。因此，可以更有效地利用可用的片外带宽，从而提高系统性能和能源效率。描述了 MemSZ 系统的两个替代多核变体。第一个变体在处理器裸片上有一个共享的最后一级缓存 (LLC)，它经过修改以存储压缩和未压缩的数据。第二个具有 3D 堆叠 DRAM 缓存，具有更大的缓存行，与压缩内存块的粒度相匹配，并且仅存储未压缩的数据。对于允许对其大部分数据进行激进近似的应用程序，MemSZ 可将基线内存流量减少高达 81%，执行时间减少高达 62%，能源成本减少高达 25%，从而为应用程序输出引入高达 1.8% 的错误. 与当前最先进的有损内存压缩设计相比，MemSZ 将执行时间、能量和内存流量分别提高了 15%、9% 和 64%。和能源成本高达 25%，给应用程序输出带来高达 1.8% 的错误。与当前最先进的有损内存压缩设计相比，MemSZ 将执行时间、能量和内存流量分别提高了 15%、9% 和 64%。和能源成本高达 25%，给应用程序输出带来高达 1.8% 的错误。与当前最先进的有损内存压缩设计相比，MemSZ 将执行时间、能量和内存流量分别提高了 15%、9% 和 64%。