OpenACC Blog

In this blog article I describe recent work to optimize an OpenACC code provided by the UK Met Office. This relatively small computational section has been developed as part of preparations to move to the new LFRic Weather Simulation Model.

In November 2018, OpenACC announced the latest update to the specification, version 2.7. This includes a number of minor updates to the previous version 2.6, in response to user requests from their experiences using OpenACC is real applications. There are many changes through the text that are intended to clarify and simplify the specification without changing its meaning. Here we'll go through the nontrivial changes and their impact. 

In this  blog, we will be discussing the history of the OpenACC GCC implementation, its availability, and enhancements to OpenACC support in GCC.  You will also learn about a recent project to assess and improve the performance of codes compiled with GCC’s OpenACC support.

GTC this year was overwhelming in size and dazzled with innovations. If you haven’t experienced the conference yet, we highly recommend you to check it out - the amount of information pouring through talks, tutorials, demos, panels, posters, startup showcases is just hard to imagine. You’ll find all you need for starting or optimizing your Deep Learning or HPC project on GPUs. 

Everyone is in a hurry today. And why not? We have CPU’s with more cores than ever and we have GPU’s with over 5,000 cores. The way to use these cores is to expose parallelism in our code. By doing that we can run faster (I don’t believe anyone has ever asked for less performance). One of the best ways to do this is to use OpenACC. OpenACC is great because it is simple to use (just “comments” in your code), allows the user to have control over the parallelization, and is portable.