# MetUM performance, ARCHER2 **URL:** \ **Category:** Unified Model\ **Tags:** ARCHER2\ **Created:** [31 August 2021 12:32 UTC](https://cms-helpdesk.ncas.ac.uk/t/metum-performance-archer2/208 "2021-08-31T12:32:56Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![aelvidge](https://avatars.discourse-cdn.com/v4/letter/a/0ea827/32.png) [@aelvidge](https://cms-helpdesk.ncas.ac.uk/u/aelvidge)\ **Post date:** [31 August 2021 12:32 UTC](https://cms-helpdesk.ncas.ac.uk/t/metum-performance-archer2/208/1 "2021-08-31T12:32:56Z")
Hi, I am in the process of completing a Technical Assessment form for ARCHER2 usage on a (non-NERC) grant proposal. For this, I require information on how well the UM scales on ARCHER2. The jobs I am proposing are high resolution regional simulations. Specifically, I need to provide a table showing how the runtime of my most computationally expensive job (I suppose the forecast jobs for my highest resolution nest) varies with the number of nodes used. I don’t suppose you have any relevant data at hand (beyond what is available here [http://cms.ncas.ac.uk/wiki/Archer2#Performance](http://cms.ncas.ac.uk/wiki/Archer2#Performance))? For what it’s worth, my high resolution jobs will be 4-km grid spacing, 70 vertical levels, 100-second timestep, Thanks, Andy ---
**Author:** ![grenville](https://dub1.discourse-cdn.com/flex013/user_avatar/cms-helpdesk.ncas.ac.uk/grenville/32/29_2.png) [@grenville](https://cms-helpdesk.ncas.ac.uk/u/grenville)\ **Post date:** [31 August 2021 13:13 UTC](https://cms-helpdesk.ncas.ac.uk/t/metum-performance-archer2/208/2 "2021-08-31T13:13:59Z")
Andy We have used the following on occasion: For N512, we get about 250,000 AU/model month. That’s for 66.8 million grid points and a 600 sec time step So, for limited area models, use 0.0037 AU/grid point and scale for the short time step, we used 150 sec for 12k and 100 sec for 4km for 12km use 0.015 AU/grid point for 4km use 0.022 AU/grid point. Roughly speaking. But we’ve not done the same for ARCHER2 - these numbers are probably good enough to estimate CUs - I’m not sure how ARCHER will view this level of detail. Grenville ---
**Author:** ![aelvidge](https://avatars.discourse-cdn.com/v4/letter/a/0ea827/32.png) [@aelvidge](https://cms-helpdesk.ncas.ac.uk/u/aelvidge)\ **Post date:** [31 August 2021 13:33 UTC](https://cms-helpdesk.ncas.ac.uk/t/metum-performance-archer2/208/3 "2021-08-31T13:33:36Z")
Thanks Grenville. In fact you sent me this information a while ago, and I have used these figures to estimate the total cost of the simulations I propose. However, this is insufficient - ARCHER2 got back to me and said they require scaling information - specifically how the runtime for a UM job varies with the number of nodes it is run on. I don’t currently have an ARCHER2 account (I use MONSooN) so can’t test this myself. So was wondering if you might have any data on this already. Perhaps not? Thanks, Andy ---
**Author:** ![grenville](https://dub1.discourse-cdn.com/flex013/user_avatar/cms-helpdesk.ncas.ac.uk/grenville/32/29_2.png) [@grenville](https://cms-helpdesk.ncas.ac.uk/u/grenville)\ **Post date:** [31 August 2021 13:51 UTC](https://cms-helpdesk.ncas.ac.uk/t/metum-performance-archer2/208/4 "2021-08-31T13:51:15Z")
You could provide scaling info from Monsoon - it’s pretty much the same as ARCHER and I believe they accept ARCHER scaling. The only scaling plots we have are at [http://cms.ncas.ac.uk/wiki/UM/Configurations/Performance#ScalingCostPlots-ARCHER](http://cms.ncas.ac.uk/wiki/UM/Configurations/Performance#ScalingCostPlots-ARCHER) Grenville ---
**Author:** ![RosalynHatcher](https://dub1.discourse-cdn.com/flex013/user_avatar/cms-helpdesk.ncas.ac.uk/rosalynhatcher/32/11_2.png) [@RosalynHatcher](https://cms-helpdesk.ncas.ac.uk/u/RosalynHatcher)\ **Post date:** [4 January 2022 08:44 UTC](https://cms-helpdesk.ncas.ac.uk/t/metum-performance-archer2/208/5 "2022-01-04T08:44:55Z")