Current-day data centers and IaaS clouds (e.g. Amazon EC2, MS Azure, Google GCE) use microprocessors that are very similar to or the same as those used in small servers and desktops. This work rethinks the design of microprocessors specifically for data center use along with how microprocessors are affected by the novel economic models that have been popularized by IaaS clouds. This talk will describe several architectural changes including how a processor can be decomposed into sub-components (e.g. ALU, Cache, Fetch Unit) that can be individually rented in IaaS clouds, how running similar programs can be taken advantage of in the data center, how architectural features such as the flavor of memory bandwidth (bursty vs. bulk) can be provisioned and sold in the data center, and novel memory architectures that enable the creation of sub-coherence domains of cache coherence across the data center.
This work has not only been simulated, but many of the discussed ideas have been implemented in one of the largest academic processors ever built, the Princeton Piton Processor. Piton is a 25-core manycore built in IBM's 32nm process technology containing over 460 Million transistors and runs full stack Debian Linux with networking.
This talk will discuss Piton along with what it takes to tape-out a complex microprocessor in an academic setting. Last, Piton has been recently open sourced as the OpenPiton project which is an expandable manycore platform which includes RTL, thousands of tests, and implementation scripts. The talk will conclude by discussing how OpenPiton is able to contribute to the burgeoning field of open source hardware.
David Wentzlaff is an Assistant Professor at Princeton University in the Electrical Engineering Department. Before joining Princeton, he completed his PhD and MS at MIT and was Lead Architect and Founder of Tilera Corporation, a multicore chip manufacturer now owned by Mellanox. Before Tilera, he was one of the architects of the Raw Processor at MIT and designed the Raw on-chip networks. David founded the MIT Factored Operating System (fos) project which focused on designing scalable operating systems for thousand core multicores and cloud computers. His work has been awarded the NSF CAREER award, the DARPA Young Faculty Award, the AFOSR Young Investigator Prize, and the Princeton E. Lawrence Keyes Faculty Advancement Award. David teaches the world's first Massively Open Online Course (MOOC) in Computer Architecture offered through Coursera. David's current research interests include how to create manycore microprocessors customized specifically for future data centers and Cloud computing environments and how to reduce the impact of computing on the environment by optimizing computer architecture for fully biodegradable substrates. He enjoys hiking and mountaineering when not designing multicore processors.
Host: Kunle Olukotun