*Music*
Quinn: El Capitan is the result of a second collaboration of the CORAL partners,
which are Oak Ridge, Argonne, and LawrenceLivermore National Laboratories.
The first collaboration resulted in Sierra, which is sited at our Lab.
The program, the NNSA program looked out beyond 2023 at our nuclear weapons needs and came up with a
number of requirements that we wanted to achieve with the El Capitan system. And
one of the key ones is that it perform an order of magnitude better on
some important calculations over Sierra in that timeframe to meet those
objectives.
Clouse: I think exascale computing is kind of
the next step in improving our computational capabilities. Y'know, why
do we need to improve our computational capabilities? Well, the NNSA complex is
facing several large modernization programs right now and these programs
will essentially introduce the most significant changes to both the nuclear
explosive package as well as the delivery system since the end of nuclear testing.
Pudliner: Ultimately, the world is in 3D. And there are serious questions in
the stockpile that have to be addressed by using 3D simulation. Another aspect is
our physical models, some physics is fundamentally 3D, we have to make
compromises when we run them in lower dimensions. We'd like to be in a position
where we're not making those compromises and to model fundamentally 3D things
with 3D simulation. A machine like El Capitan will enable us to, in some cases,
take those 3D simulations and turn them around on the same kind of time scale
that today's 2D simulations are turned around. That makes them a design
iteration tool, and enables us to answer the questions that we need to answer for
the stockpile in a workday kind of turnaround.
Rieben: Preparing for an exascale system
like El Capitan is a major challenge. Fortunately the Department of Energy ASC
program anticipated this and got the process started by investing in the
necessary pieces. So this includes getting our current production codes
ready but also starting new codes, next generation codes.
Quinn: We have awarded two
contracts with Cray. One is a non-recurring engineering, or you might
think of it as an R&D contract, and we've awarded a contract that actually
builds and delivers the El Capitan system. The purpose of that R&D contract
is to develop and pull forward some innovations that that Cray and their
subcontractors have in mind for that system. So, in order to meet some of our
objectives, we couldn't just wait and buy off-the-shelf, we really needed to push
the technology in some key ways. So we have both hardware and software
development going on in that NRA contract.
Rieben: Similar to how we handled
the Sierra platform, we will be engaging with a center of excellence for the El
Capitan system. This enables us to work directly with hardware experts in
getting our algorithms and our software ready for this new platform.
Clouse: If you look at the increase of computation capability that's occurred over the last
couple decades: orders of magnitude increase, but we can't go up in orders of
magnitude use of power and that's really what's driving these new architectures
is trying to deliver more computation capability without driving up the power
costs. I think El Capitan will be a signature system into being able to
deliver exaflop capabilities within a power envelope that we can afford.
Bailey: For material science in general, we do have large collaborations across national
labs, within an NNSA and also with Office of Science, and those are really big
efforts involving a lot of researchers. I really do think that El Capitan will
enable those collaborations to take next steps into learning more about the
physics and I think it's gonna benefit the entire DOE organization.