The 2nd Cache Replacement Championship

The Objective

Compare different cache replacement algorithms for a last level cache in a common framework. Replacement algorithms will be evaluated for both private and shared last level caches with and without a data prefetcher. The algorithms must be implemented within a fixed storage budget (32KB per core) as specified in the competition rules. Submissions will be evaluated based on their performance using the framework provided by the organizing committee. Submissions will be evaluated under the following four configurations:

  • Single core with 2 MB LLC without a prefetcher.
  • Single core with 2 MB LLC with L1/L2 data prefetchers.
  • A 4-core configuration with 8 MB of shared LLC without a prefetcher.
  • A 4-core configuration with 8 MB of shared LLC with L1/L2 prefetchers.


The following are the rules for the 2nd Cache Replacement Championship:

  • All replacement policies must contain less than or equal to 32KB worth of state per core.
  • All replacement policies must use only the published simulator interface functions (ie. no disassembly of the simulator to extract extra information)
  • Replacement policies must not violate causality (ie. the policy must not pre-parse the trace or other such cheats).
  • To be considered an eligible submission, both the four page writeup and the (working) source code must be submitted by the submission deadline of Apr. 14th (submission details to follow).
  • Submissions to CRC2 will not be considered archival, thus do not count against future conference/journal publication.
  • Concurrent submission with ACM/IEEE Micro'17 is allowed. In all such concurrent submissions, however, the PC chairs of both Micro and CRC2 must be made aware of the submission concurrency before the Micro deadline.
  • Authors retain copyright of all submissions and code, but must allow them to be published on the CRC-2 website.

Important Dates

  • Feb 6: Competition simulator framework released.
  • April 14 11:59PM Central Time: Submissions are due with a 300 word abstract, replacement modules, and 4 page write-up.
  • April 28: Author notification.
  • June 25: CRC-2 Workshop at ISCA 2017.


The champion, the replacement policy with the best geomean speedup versus baseline across all traces and configurations, will receive a trophy commemorating their triumph.

The program committee will also select the best technical paper from all submissions, which does not necessarily have to be that of the champion. All source code, write-ups and performance results will be made publicly available through the CRC-2 website.


The framework and trace generating software is downloaded by clicking the following link:


Documentation on the simulator can be found in the README and description files destributed along with the framework. We also include a couple of example replacement policies for participants, so feel free to join the competition and assert your dominance!

Note, the current framework contains a handful of pre-captured traces for use in the development of your policies. We will release additional traces for testing by the end of the month.

Recent Changes
February 7th: Updated to version 1.1. Fixed compilation issue on Ubuntu 16.10 with gcc 6.2.
February 10th: Updated to version 1.2. Fixed trace generator.
March 17th: Released version 2.0.
Increased core clock frequency from 3.2GHz to 4.5GHz.
Fixed prefetch latency.
Fixed DRAM address mapping.


Go to the following link and make an account on the CRC2 HotCRP website to submit your 300 word abstract and 4-page write up. Submit your replacement module by emailing your code to in a zipped format. Submissions are due by April 14th at 11:59PM Central Time. The review process of CRC2 will be optionally double blind. Papers may include author names or not as desired by the authors.


If you have not already done so, please join the CRC-2 mailing list by sending an empty email to:

You do not need a google account - you only need to subscribe to the mailing list. When prompted, type in the email you want to use for the CRC-2 subscription.

This mailing list will be used for any announcements regarding the competition, any simulation infrastructure updates, and allows participants to post questions or report problems.

Competition Chairs

Paul V. GratzProgram Committee ChairTexas A&M University
Jinchun KimOrganizing Committe ChairTexas A&M University
Gino ChaconSubmission ChairTexas A&M University

Organizing Committee

Name Affiliation
Alaa R. Alameldeen Intel
Chris Wilkerson Intel
Seth Pugsley Intel
Aamer Jaleel Nvidia
Babak Falsafi Ecole Polytechnique Federale de Lausanne
Mark Sutherland Ecole Polytechnique Federale de Lausanne
Javier Picorel Ecole Polytechnique Federale de Lausanne

Program Committee

Name Affiliation
Mike Ferdman Stony Brook University
Daniel Jiménez Texas A&M University
Moinuddin Qureshi Georgia Tech
Eric Rotenberg North Carolina State University
Carole-Jean Wu Arizona State University
Akanksha Jain University of Texas at Austin
Babak Falsafi Ecole Polytechnique Federale de Lausanne