Mining Bitcoins using a Heterogeneous Computer Architecture

Abstract

Recent years have seen the emergence of a new class of currencies, called\ncryptocurrencies. These currencies use cryptography to provide security\nand peer-to-peer networking to provide a decentralized system. Bitcoin is\nthe most popular of these currencies. It uses a two-pass\nSHA-256 hash at its core. Producing new bitcoins is done through a process\nreferred to as "mining", which involves a brute-force search for a hash with\na specific value. This process requires large amounts of computing power.\n\nCurrent-generation hardware for bitcoin mining includes highly-optimized\nASIC chips which provide huge amounts of performance. However, designers of\nsuch chips are having problems with delivering enough power and cooling\nto the chips. To alleviate this problem, this thesis looks at the possibilities\nof using heterogeneous computing to reduce power consumption and produce a more\nenergy-efficient mining solution.\n\nA SHA-256 accelerator and a DMA module is developed and integrated into a tile for\nthe Single-ISA Heterogeneous MAny-core Computer, SHMAC, and a system with\nmultiple cores is used to exploit the thread-level parallelism provided by\nthe platform. The system is tested using a benchmark to find out what performance\nand energy efficiency can be expected when using the system for bitcoin mining.\n\nThe results show a maximum performance of 175,7 kH/s when running the benchmark\napplication on 14 cores using the SHA-256 accelerator and the DMA module. The best\nenergy efficiency was obtained when running on 14 cores without the DMA enabled,\nat 163,2 kH/J. The results does not compare well to specialized FPGA-based\nbitcoin miners, but demonstrates the SHMAC platform's large degree of thread-level parallelism\nwhich can be better exploited in other applications.