As part the regular software upgrade cycle, ARCHER will remove the Cray cce8.2.1 compiler on June 24th. cce8.2.1 has been the UM compiler since ARCHER became operational and we have maintained its use to minimize possible disruption but it does appear to be a source of OOM errors in some long-running UM jobs. These OOM errors have not appeared in jobs running code compiled with later Cray compilers, so it is timely to upgrade to the current ARCHER default - cce8.3.7.

cce8.3.7 GCOMs (gcom3.8 gcom4.2 gcom4.5 gcom4.6 gcom4.7 gcom5.1) are in $UMDIR/gcom/cce8.3.7

Include MPICH_NO_BUFFER_ALIAS_CHECK=1

Compiler upgrade notes

UM Version	Description	cce8.3.7 jobid	cce8.2.1 jobid	Comments
8.2	N96 HadGEM3A	xlnia	xleha	Needed to reduce optimization on convection to O1 - didn't look for specific routine - only checked with 1 start file
8.2	N512 - the SWAMMA driving model	xjjzv	xjjzw	OOM errors seen (see ticket #1535); worked as is
8.2	12km SWAMMA	xlnib	xlehb	OOM errors in the cce8.2.1 job; worked as is
8.4	N96 GA?	xjfvy	xlchx	OOM errors in the cce8.2.1 job; needed fix for bug in locate_hdps.F90 - had to cast array indices to INTS - change added to the ncas branch see ticket #1485
6.6.3	HadGEM2-AMIP	xlnic	xjgcc	runs OK built with -g - blows up somewhere with 8.2.1 settings — large_scale_cloud::ls_arcld is the culprit; build this with -O0 and the model runs OK
6.6.3	HadGEM2-ES	xlnid	xjgcu	worked as is
6.6.3	HadGEM2-CC	xlnie	xjgcf	needs large_scale_cloud::ls_arcld compiled with -O0 and the model runs OK
7.3	HadGEM3-A r2.0	xlnif	xjeya	worked as is
8.2	N96 GA4.0 AMIP	xlnnb	xjeye	No modifications required
8.4	HG3A GA4.0	xlnnc	xjeyf	No modifications required
8.6	HG3A GA6.0	xloba	xjvpu	No modifications required