Gulp需要很长时间来执行任务

Question

我正试图第一次尝试Gulp，并且无法弄清楚为什么在加载包和运行任务时需要这么长时间，每次约48秒。不确定平均有多少包，但我想我需要所有包。我一直试图通过一些例子来提高性能但是我被困在同一个地方 我非常感谢任何建议！ 这是我的 gulpfile.js ：

            var gulp = require('gulp'),
            runSequence = require('run-sequence'),
            templateCache = require('gulp-angular-templatecache'),
            sass = require('gulp-sass'),
            autoprefixer = require('gulp-autoprefixer'),
            rename = require("gulp-rename")
            browserify = require('browserify'),
            concat = require('gulp-concat'),
            addStream = require('add-stream'),
            source = require('vinyl-source-stream'),
            buffer = require('vinyl-buffer'),
            imagemin = require('gulp-imagemin'),
            browserSync = require('browser-sync'),
            reload = browserSync.reload,
            ngAnnotate = require('gulp-ng-annotate'),
            uglify = require('gulp-uglify'),
            jshint = require('gulp-jshint'),
            htmlmin = require('gulp-html-minifier'),
            del = require('del');


            function templates() {
                return gulp.src('./app/views/**/*.html')
                    .pipe(templateCache({
                                module: 'portfolio'
                            }));
            }

            gulp.task('clean:dist', function() {
              return del.sync('dist/assets/');
            });

            gulp.task('jshint', function() {
                 return gulp.src('./app/js/**/*.js')
                    .pipe(jshint())
                    .pipe(jshint.reporter('default'))
            });

            gulp.task('browserify', function() { 

                    return  browserify('./app/app.js')
                    .bundle()
                    .pipe(source('main.js'))
                    .pipe(buffer())
                    .pipe(ngAnnotate())
                    .pipe(addStream.obj(templates()))
                    .pipe(concat('main.js'))
                    .pipe(uglify())
                    .pipe(rename({ suffix: '.min' }))
                    .pipe(gulp.dest('./dist/assets/js/'))
            });

            gulp.task('sass', function() {
                return gulp.src('./app/css/main.scss')
                    .pipe(sass({outputStyle: 'compressed'}).on('error', sass.logError))
                    .pipe(autoprefixer())
                    .pipe(rename({ suffix: '.min' }))
                    .pipe(gulp.dest('./dist/assets/css'))
            });

            gulp.task('images', function() {
                return gulp.src('./app/img/**/*.{png,jpg,gif,svg}')
                .pipe(imagemin({ optimizationLevel: 3, progressive: true, interlaced: true }))
                .pipe(gulp.dest('./dist/assets/img'))
            });

            gulp.task('copyfonts', function() {
               gulp.src('./app/css/fonts/**/*.*')
               .pipe(gulp.dest('./dist/assets/fonts'));
            });

            gulp.task('copy-index-html', function() {
                gulp.src('./app/index.html')
                .pipe(htmlmin({collapseWhitespace: true}))
                .pipe(gulp.dest('./dist'));
            });

            gulp.task('serve', function() {
                browserSync({
                    server: {
                        baseDir: './dist'
                    }
                });

                gulp.watch('app/js/**/*.js', ['browserify', reload]);
                gulp.watch('app/css/**/*.scss', ['sass', reload]);
                gulp.watch('app/views/**/*.html', [reload]);
            });

            gulp.task('bs-reload', function () {
                browserSync.reload();
            });

            gulp.task('default', function(callback) {
              runSequence('clean:dist',  'jshint', ['browserify', 'sass', 'images','copy-index-html','copyfonts'], 'serve', callback);
            });

Gulp performance (image link)