gulp.task() much slower than gulp.watch() -

i have gulpfile.js configured tasks compile js, less , add auto-version strings html.

when start gulp default task (gulp) save js or less files watch() method handles each corresponding task in reasonable amount of time. however, when try run these tasks manually task() (gulp build) runs 3 @ once process incredibly slow, 9x slower exact.

below source entire file, there glaring i'm missing here? seem difficult identify causing slow build command:

/**  * build process less, js & html  */  "use strict";  const gulp = require( 'gulp' ); const include = require( 'gulp-codekit' ); const less = require( 'gulp-less' ); const path = require( 'path' ); const uglify = require( 'gulp-uglify' ); const pump = require( 'pump' ); const ngannotate = require( 'gulp-ng-annotate' ); const autoprefixer = require( 'gulp-autoprefixer' ); const cleancss = require( 'gulp-clean-css' ); const rename = require( 'gulp-rename' ); const injectversion = require( './build/inject-version' );  // build tasks gulp.task( "less", compileless ); gulp.task( "js", compilejs ); gulp.task( "html", compilehtml ); gulp.task( "default", watch ); gulp.task( "build", [ 'less', 'js', 'html' ] );  // error handler function pumpdone( error ) {     if ( !error ) return;      return new util.pluginerror( 'test', error, {         showstack: true     } ); }  // compile javascript function compilejs() {     return pump( [         gulp.src( 'ng/main.js' ),         include(),         ngannotate(),         uglify(),         gulp.dest( 'dist/js' )     ], pumpdone ); }  // compile less function compileless() {     return pump( [         gulp.src( 'less/main.less' ),         less( {             paths: [ path.join( __dirname, 'less' ) ]         } ),         autoprefixer( {             browsers: [ 'last 2 versions' ],             cascade: false         } ),         cleancss( {             compatibility: 'ie9'         } ),         gulp.dest( 'dist/css' )     ], pumpdone ); }  // compile html function compilehtml() {     return pump( [         gulp.src( 'index.tmp' ),         injectversion(),         rename( {             extname: '.html'         } ),         gulp.dest( '.' )     ], pumpdone ); }  // watch files , run tasks if change function watch() {     gulp.watch( 'less/*.less', [ 'less' ] );     gulp.watch( 'ng/**/*.less', [ 'less' ] );     gulp.watch( 'ng/**/*.js', [ 'js' ] );     gulp.watch( 'dist/**/*.js', [ 'html' ] );     gulp.watch( 'dist/**/*.css', [ 'html' ] );     gulp.watch( '*.tmp', [ 'html' ] ); } 

any appreciated, time.