Input from the experiments:

• ALICE
  • less than 2% of the cores do not support x86_64-v3, but some sites are much more affected than most
  • unclear how much benefit x86_64-v3 would bring to which workflows → some tests are planned

• ATLAS
  • 60% x86_64-v3
  • 38% x86_64-v4

• CMS
  • do their own builds of GEANT and ROOT
  • older HW remains used for older data and MC
  • concerned that shared sites might effectively be forced to decommission old HW that could still be used by CMS

• LHCb
  • about 2% of the cores do not support x86_64-v3
  • such resources can still be filled with older workloads
  • no significant performance improvements expected from AVX2
  • a priori no objection against assuming x86_64-v3 for new builds of GEANT and ROOT