webpackDevMiddleware & webpackHotMiddleware slow down the server

Question

I've added the hot-reload on an express app in using webpackDevMiddleware & webpackHotMiddleware but I notice that this 2 middleware slow down the app, I think is normal that the first start should be slower becuase I need to compile everything but after compile the files is just matter to serve them....same code without these 2 middleware is respond very quick, after add them it slow down a lot...I can on chrome console some file in pending for some seconds...I don;t think this is related to any wrong webpack configuration because the problem is after the compilation, simply everytime I reload the page it takes 20sec to load...any suggestions?

app.use(webpackDevMiddleware(compiler, {
  noInfo: true,
  publicPath: config.output.publicPath
}));
app.use(webpackHotMiddleware(compiler));