# Docker (moby-engine) performance deficit avoidable?

**URL:** <https://forums.docker.com/t/docker-moby-engine-performance-deficit-avoidable/104552>\
**Category:** General\
**Tags:** docker\
**Created:** [February 16, 2021, 8:48pm UTC](https://forums.docker.com/t/docker-moby-engine-performance-deficit-avoidable/104552 "2021-02-16T20:48:49Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![dockervoidx](https://sea3.discourse-cdn.com/docker/user_avatar/forums.docker.com/dockervoidx/32/32492_2.png) [@dockervoidx](https://forums.docker.com/u/dockervoidx)\
**Post date:** [February 16, 2021, 8:48pm UTC](https://forums.docker.com/t/docker-moby-engine-performance-deficit-avoidable/104552/1 "2021-02-16T20:48:49Z")

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Hello everyone,

I was doing some benchmarking between my docker container an a bare-metal install of different software I use. I compared a CentOS 7 install to a CentOS7 docker and a Fedora 33 install to a Fedora 33 docker.

The setup is as followed for the docker:

- CentOS 7 docker is started with sbin/init and accessed using docker exec

- Fedora 32 docker is started with /bin/bash

Both are ran in a VM (meaning I have a Fedora 33 VM and a CentOS7 VM, but both centos and fedora docker are being ran on the Fedora 33 VM)

So the software I ran for the test are Ansys Fluent and StarCCM+ for centos and Openfoam for Fedora.

For the ansys fluent test:

`Ansys Fluent Concorde Case (8 cores)`  
`5960x (linux CentOS7 docker in Fedora 33 VM V19.3) = 142.939 seconds (for 140 iterations)`  
`5960x (linux CentOS7 docker in Fedora 33 VM V19.13) = 393.108 seconds (287 Iterations, Check Mesh fixed 10% bad cells for 4 passthroughs twice)`  
`5960x (linux CentOS7 VM Ansys R19.3) = 132.494 seconds (for 140 iterations)`  
`5960x (linux CentOS7 VM Ansys R19.3) = 383.644 seconds (287 Iterations, Check Mesh fixed 10% bad cells for 4 passthroughs twice)`

For StarCCM+ test:

`StarCCM+`  
`Blade Element Helicoptor Method (8 core):`  
`5960x (linux CentOS7 docker in Fedora 33 VM V10.03.065) = 10684.45 seconds (or 8 times total cpu time) or 1335.56 seconds total`  
`5960x (linux CentOS7 VM V10.03.065) = 9514.61 Seconds (or 8 times total cpu time) or 1189.326 seconds total`

For Openfoam test:

`OpenFOAM-7 Incompressible SimpleFOAM Motorbike (6 core):`  
`5960x (linux Fedora 32 docker in Fodera 33 VM (OFv7) = 98.52 seconds (SnappyHexMesh) and 228.77 seconds (SimpleFoam)`  
`5960x (linux Fodera 33 VM (OFv7) = 99.22 seconds (SnappyHexMesh) and 213.5 seconds (SimpleFoam)` `OpenFOAM-v1912 Incompressible SimpleFOAM Motorbike (6 core):`  
`5960x (linux Fedora 32 docker in Fodera 33 VM (OFv1912) = 77.56 seconds (SnappyHexMesh) and 261.73 seconds (SimpleFoam)`  
`5960x (linux Fodera 33 VM (OFv1912) = 73.78 seconds (SnappyHexMesh) and 229.55 seconds (SimpleFoam)`  
`OpenFOAM-v2012 Incompressible SimpleFOAM Motorbike (6 core):`  
`5960x (linux Fedora 32 docker in Fodera 33 VM (OFv2012) = 77.08 seconds (SnappyHexMesh) and 246.53 seconds (SimpleFoam)`  
`5960x (linux Fodera 33 VM (OFv2012) = 75.2 seconds (SnappyHexMesh) and 236.8 seconds (SimpleFoam)`

Based on those numbers I am looking at:

`fluent (concorde, 140 iteration) docker perf hit = 7.31 %`  
`fluent (concorde, 287 iterations) docker perf hit = 2.41 %`  
`StarCCM+ (Blade Element Method Helicopter) docker perf hit = 10.95%`  
`Openfoam 7 (motorbike) docker perf hit = 6.67%`  
`Openfoam 1912 (motorbike) docker perf hit = 12.23%`  
`Openfoam 2012 (motorbike) docker perf hit = 3.95%`

So is that a normal overhead to expect? I believe the delta will increase/decrease depending on simulations. Is it possible to get an almost 0% (or less than 0.1%) delta?

Here is the script I use to launch CentOS docker: [My script](https://pastebin.com/S5v9P20m)