Pipeline GPU PME Spline/Spread with PP Comms

[alexxy/gromacs.git] / docs / release-notes / 2022 / major / performance.rst

diff --git a/docs/release-notes/2022/major/performance.rst b/docs/release-notes/2022/major/performance.rst
index b4f7529794f2b0798f33975eaf1b56d1edf1452c..247715ff239945f794d9eaabebac97acbb9baaf1 100644 (file)
--- a/docs/release-notes/2022/major/performance.rst
+++ b/docs/release-notes/2022/major/performance.rst
@@ -7,3 +7,38 @@ Performance improvements
    Also, please use the syntax :issue:`number` to reference issues on GitLab, without the
    a space between the colon and number!
 
+Dynamic pairlist generation for energy minimization
+"""""""""""""""""""""""""""""""""""""""""""""""""""
+
+With energy minimization, the pairlist, and domain decomposition when running
+in parallel, is now performed when at least one atom has moved more than the
+half the pairlist buffer size. The pairlist used to be constructed every step.
+
+Nonbonded free-energy kernels use SIMD
+""""""""""""""""""""""""""""""""""""""
+
+Free energy calculation performance is improved by making the nonbonded free-energy
+kernels SIMD accelerated. On AVX2-256 these kernels are 4 to 8 times as fast.
+This should give a noticeable speed-up for most systems, especially if the
+perturbed interaction calculations were a bottleneck. This is particularly the
+case when using GPUs, where the performance improvement of free-energy runs is
+up to a factor of 3.
+
+:issue:`2875`
+:issue:`742`
+
+       
+PME-PP GPU Direct Communication Pipelining
+""""""""""""""""""""""""""""""""""""""
+
+For multi-GPU runs with direct PME-PP GPU comunication enabled, the
+PME rank can now pipeline the coordinate transfers with computation in
+the PME Spread and Spline kernel (where the coordinates are
+consumed). The data from each transfer is handled seperately, allowing
+computation and communication to be overlapped. This is expected to
+have most benefit on systems where hardware communication interfaces
+are shared between multiple GPUs, e.g. PCIe within multi-GPU servers
+or Infiniband across multiple nodes.
+
+:issue:`3969`
+