Running Multiple Instances of V-REP

[abachoo]

Hello CoppeliaSIm

I am using V-REP 3.6.2 (rev 0) 64-bit on Windows 10. I have 16GB of RAM and an i7 8850H CPU @ 2.6 GHz.

I implemented a simulation for grasping objects. I have observed the following when running V-REP on the command line in headless mode:
1. If I run a single instance, my simulation takes around 150s.
2. If I run two separate instances in parallel with each doing the same simulation, each simulation takes around 300s. I have two separate folders with all the V-REP dlls and my simulation data copied into each folder so there is no sharing of data.

It seems to me that running 2 separate V-REP instances in parallel offers no speed improvement over a single instance. I am using the ODE physics engine. I also observed that the CPU load and RAM overhead are low for each instance.

Can you explain to me what might be happening, and how to get a speedup with multiple V-REP instances?

[coppelia]

Hello,

hum... maybe the OS is assigning the same CPU to the two instances. Or the simulation is depending on something that makes the two instances linked. I just had a quick test with the youBotAndHanoiTower scene, and running in parallel executes faster than running sequentially the same

Cheers

[abachoo]

Can you provide me with your system specifications i.e. OS and V-REP versions? Do you know of any issues running multiple instances?

Thank you.

[coppelia]

I tested on Windows 10 with CoppeliaSim V4.0.0

Cheers