# Session 6: Breakout room 3: Model Configurations/ development - ACCESS-CM3/ESM3 **URL:** \ **Category:** CMIP7 Workshop\ **Tags:** workshop, cmip7\ **Created:** [1 March 2023 00:00 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507 "2023-03-01T00:00:06Z")\ **Posts on this page:** 15\ **Page:** 3
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:42 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/41 "2023-03-01T01:42:03Z")
?: incremental dev of CM2 and ESM1.5 to get to ESM2 - eg biennial ENSO in CM2 ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:45 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/42 "2023-03-01T01:45:17Z")
BE: what about NCI system resources? Is this a major constraint on ambition? ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:46 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/43 "2023-03-01T01:46:27Z")
AH: system resources (SU) are not the main constraint - the main constraint is speed, ie walltime ie parallel scalability ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:48 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/44 "2023-03-01T01:48:18Z")
BE: new capacity has just come online; ~3yr timescale for more TZ: core speed, not number of cores, would help ?: in terms of department role - could influence NCRIS and NCI resources i its clear this is needed for CMIP7 ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:49 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/45 "2023-03-01T01:49:20Z")
DE: new cores have new architecture - many cores per CPU - so may be faster - would take experimentation, but not a factor of 2 ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:49 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/46 "2023-03-01T01:49:58Z")
HR: system will be under pressure once CMIP7 production runs are underway ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:51 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/47 "2023-03-01T01:51:01Z")
BE: also what data resources BGF: Finland has 5M people but the worlds’s 3rd fastest computer - can we lift the bar ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:51 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/48 "2023-03-01T01:51:34Z")
RH: can we spin up component-wise to speed it up eg spin up ocean separately > [@Decoupling the ACCESS ESM for long spin-up](https://forum.access-hive.org.au/t/decoupling-the-access-esm-for-long-spin-up/446): > > We are planning to run some glacial experiments with the ACCESS ESM. Since the boundary conditions are quite different from pre-industrial/interglacial conditions, we will need to run the model for more than 2000 years. We were thus wondering if there were some ways the spin-up could be “accelerated”? ie the atmospheric model is the slow and heavy part of the ACCESS-ESM but it is the ocean that takes a long time to equilibrate. Would there be a way to increase the length of the atm. time step o… ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:52 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/49 "2023-03-01T01:52:21Z")
ME: ~5x slower than NCAR model - but due to fewer vertical levels ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:53 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/50 "2023-03-01T01:53:04Z")
?: NCAR is going to 80 levels. But what we need is fast aerosols ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:53 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/51 "2023-03-01T01:53:36Z")
TZ: need to map out options in terms of model speed ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:55 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/52 "2023-03-01T01:55:27Z")
?: timeline: must consider dev time for benchmarking systems - currently doesn’t exist - we really need this because we weren’t able to do performance tests of all the physics options available - if we could run multiple sensitivity expts in parallel we could make a lot more progress, ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:56 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/53 "2023-03-01T01:56:58Z")
?: e.g to solve biennial enso - many ~50yr coupled runs to test parameter sensitivity ---
**Author:** ![aekiss](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/aekiss/32/46_2.png) [@aekiss](https://forum.access-hive.org.au/u/aekiss)\ **Post date:** [1 March 2023 01:58 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/54 "2023-03-01T01:58:30Z")
?: as well as IC ensembles, could do parameter ensembles. Could put Machine learning onto it ---
**Author:** ![MATTENGLAND](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/mattengland/32/451_2.png) [@MATTENGLAND](https://forum.access-hive.org.au/u/MATTENGLAND)\ **Post date:** [1 March 2023 02:02 UTC](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507/56 "2023-03-01T02:02:03Z")
Oops, didn’t mean to delete this post: attempt 2: I have also heard that the UM atmospheric model is a significant factor as to why ACCESS runs much slower cf. NCAR. [Previous page](https://forum.access-hive.org.au/t/session-6-breakout-room-3-model-configurations-development-access-cm3-esm3/507.md?page=2)