Docker image build is 3 times slower than the normal build

[Paul123]

I’ve received a response from them. They recommended using machine executors. As mentioned by @eliasdorneles the problem persists even with machine executors.
This is what I’ve tried:
Comparison of build time (the npm run build command):

Docker executor: 14783ms + 21555ms = 36338ms (36.33 seconds in total)
Machine executor-docker build command: 25194ms + 42171ms = 67365ms (67.365 seconds in total)
Machine executor-docker run command: 25188ms + 43326ms = 68514ms (68.514 seconds in total)

Edit:
Added config.yml

@config.yml

# Testing the performance of docker build vs normal build
version: 2

jobs:
  job1:
    machine:
      image: circleci/classic:latest
    steps:
    - run:
        name: Build from dockerfile
        #        Dockerfile:
        #
        #        # Same base image as in config.yml
        #        FROM circleci/node:8.11.1
        #        # cd to home/circleci to avoid any problems
        #        WORKDIR /home/circleci
        #        # Run the same commands
        #        RUN git clone https://github.com/cezerin/cezerin && cd cezerin && npm i && npm run build

        command: docker build https://gist.githubusercontent.com/PaulGgithub/c4359495a31961e8217fb463756444c9/raw/d01b96d7a3cb093d5bb05a47e656711373afc558/Dockerfile
        #################################################
        #    Spinning up a container and running the same commands as in step 1. Notice how slow they are executing.
        #    Build inside container
    - run:
        name: Build with docker by executing commands inside a container
        command: >
          docker run -it circleci/node:8.11.1 /bin/bash -c
          "cd home/circleci/ && git clone https://github.com/cezerin/cezerin && cd cezerin && npm i && npm run build"

workflows:
  version: 2

  tests_to_run:
    jobs:
    - job1

[Paul123]

We are stuck with building more slowly on the remote docker executor. At least when using webpack to build the bundle.

This is the final mail received from them:

Do you agree that the remote docker machine are slower than the docker executor?

For your use case I would agree, based on all the metrics we’ve reviewed together in this ticket, that compiling your application is faster on the docker executor.

Is it possible to have access to remote docker machine of the same performance as the docker executor? It will speed-up our tests significantly.

No, that is not possible.