Monte-Carlo setup:

• Throwing one photon/electron per event
• y2009 geometry tag (EEMC geometry v6.1)
• Full STAR geometry configurations with and without LOW_EM option
• Throwing particles flat in eta (1.08, 2.0), phi (0, 2pi), and energy (5-35 GeV)
• ~50K/per particle type, 250 events per job, 200 jobs

Geometry configurations

1. red: without LOW_EM option
2. black: with LOW_EM option
3. circles - electrons, squares - photons

Figure 1: (left) time/event distribution, (right) average time for the particle type

Conclusion: for single particle Monte-Carlo required time in starsim
with LOW_EM option is ~ 2.6 times higher.