Which PhysicsOverflow discussion pages have a submission rate of more then 8,000 per month?
ArXiv
Title: ArXiv
Passage: arXiv (pronounced "archive") is a repository of electronic preprints, known as e-prints, of scientific papers in the fields of mathematics, physics, astronomy, computer science, quantitative biology, statistics, and quantitative finance, which can be accessed online.  In many fields of mathematics and physics, almost all scientific papers are self-archived on the arXiv repository.  Begun on August 14, 1991, arXiv.org passed the half-million article milestone on October 3, 2008, and hit a million by the end of 2014.  By 2014 the submission rate had grown to more than 8,000 per month.
Title: PhysicsOverflow
Passage: PhysicsOverflow is a physics website that serves as a post-publication open peer review platform for research papers in physics, as well as a collaborative blog and online community of physicists.  It allows users to ask, answer and comment on graduate-level physics questions, post and review manuscripts from ArXiv (which lists PhysicsOverflow discussion pages among its trackbacks) and other sources, and vote on both forms of content.
Title: Chessgames.com
Passage: Chessgames.com is an Internet chess community with over 224,000 members.  The site maintains a large database of chess games, where each game has its own discussion page for comments and analysis.  Limited primarily to games where at least one player is of master strength, the database begins with the earliest known recorded games and is updated with games from current top-level tournaments.  Basic membership is free, and the site is open to players at all levels of ability, with additional features available for Premium members.  While the primary purpose of Chessgames.com is to provide an outlet for chess discussion and analysis, consultation games are periodically organized with teams of members playing either other teams of members or very strong masters, including a former US champion and two former world correspondence champions.  Members can maintain their own discussion pages, and there are features to assist study of openings, endgames and sacrifices.  The front page also features a puzzle of the day, player of the day, and game of the day, the puzzle varying in difficulty throughout the week from "very easy" on Mondays to "insane" on Sundays.
ArXiv PhysicsOverflow