50 Journal of Digital Information Management  Volume 15 Number 2  April 2017 Journal of Digital Information Management Teaching The Microprocessors Systems Focused on Societal Challenges: Designing of Performant Cache Replacement Algorithms as Green Informa- tion Technology (IT) Solution Adrian Florea 1 “Lucian Blaga” University of Sibiu, Computer Science and Electrical Engineering Department Sibiu, Romania adrian.florea@ulbsibiu.ro ABSTRACT: In the last decades, beside Education, Information & Communication Technology was, and will continue to be, the engine of evolution and development of society. The main goal is to achieve a better world for all of us, raising living standards using ubiquitous computing systems of any type (desktop, laptop, server, high performance computing data centers, smart phones and other portable multimedia devices, embedded systems, etc.). In order to keep this evolutionary trend should be understood the technical challenges targeting each component of the computer system, in particular the microprocessor – as known as the “computer brain”. The formal learning of discipline entitled “Microprocessors Systems” supposes that for addressing the technical challenges of microprocessors it should be discussed, analyzed and understood the current major societal challenges, and mainly the requirement of cutting down the energy consumption and of reducing our carbon footprint. In this sense it aims to develop applications and computing systems that fall within the Green ICT paradigm that means using hardware/software technology efficiently in the same time with providing economic viability, social responsibility and clean environmental impact. The work that underlies this research paper fall into the category of “Green by IT” aiming to reduce the environmental impact of operations using IT and by efficient resource usage management. More precisely, we intend to present a solution of reducing the video traffic on the Internet by designing an appropriate algorithms of cache blocks replacement which reduces the cache miss accesses in social media data storage centres. This not only decreases the video-retrieval time pleasing the user, but also will reduce the energy consumption with world-wide social benefits. By implementing performant cache replacement algorithms we will accelerate the search process of videos in YouTube and we will measure the Internet traffic exemption (in MB) if the cache miss rate decreases (for each particular algorithm) and we will also estimate how much energy is saved by the data centers of search engines. This has a very positive social impact by contributing to maintaining a clean environment, given that the resource requirements (storage and network bandwidth) of social media are growing. Subject Categories and Descriptors [C.5.3 Microcomputers]: Microprocessors; [K.3.2 Computer and Information Science Education]; [ H.3.5 Online Information Services Web-based services] General Terms Microprocessors, Web-based Education, Internet, Information and Commmunication Technology Keywords: Cache, YouTube, Microprocessors System, Societal challenges, Teaching, Energy, Environment. Received: 11 December 2016, Revised 14 January 2017; Accepted 24 January 2017