Reorganization of ReadoutElements: goal – optimize data access (algorithm timing!) Mdt example now: MdtReadoutElement = 1 multilayer MdtPrepDataCollection contains data corresponding to 2 MdtReadoutElements for rel. 14.x.0 keep MdtReadoutElements purely readout geometry – no link to raw geometry volumes add MdtDetectorElements holding pointers to 2 MdtReadoutElements MdtPrepDataCollection contains data corresponding to 1 MdtDetectorElement First implementation

Reorganization of ReadoutElements: goal – optimize data access (algorithm timing!) test algorithm with a old and new-style access to tube center use callgrind for algorithm profiling 3.04% of Job cpu for processCollectionOld 1.24% manager->getMdtReadoutElement [identifier decoding] 0.83% MdtReadoutElement->center(Identifier) [identifier decoding] 1.49% of job cpu for processCollection 1.01% MdtDetectorElement->center(Identifier) 0.xx% x 3 MdtIdHelper->multilayer/tubeLayer/tube(Identifier) 0.34% MdtReadoutElement->center(tubeLayer, tube) MuonGeoModel in opt mode gain 50% test is sensitive only if GeoModel cache is filled init time more details in http://indico.cern.ch/getFile.py/access?contribId=5&resId=0&materialId=slides&confId=28777

Clash survey Dennis Wright recently joined the Atlas Simulation team and started a systematic survey of the Muon Geometry clashes in the ideal layout (R01) concentrating on active volumes as a start identified several small clashes ~0.1nm between nearby volumes (shared boundaries) introduced small tolerances removing the problems fixes will go in 14.1.0 possibly he will take care of implementing cutouts in active volumes