Backbone vs. Simple JavaScript Inheritance

I am surprised by your experience, as there are Backbone projects which have used considerably more objects to no ill effect.

Backbone's three major components, Models/Collections, Views and Events do take some planning to coordinate effectively, but that's part of laying out your application.

Also, using bare JS objects is not an anti-pattern in Backbone. Use Models/Collections when you need to manage data, Views when you need to monitor parts of the DOM, and Events to manage messages between your components. Apply as necessary.

P.S. Model.get is literally a single line of bare JS object property access: http://backbonejs.org/docs/backbone.html#section-38 but if you have a lot of events, or validations conditioned to fire on attribute changes, that may effect how long it takes your setters to run (http://backbonejs.org/docs/backbone.html#section-41 )

Backbone's View is incredibly slow and is very ill-suited for views that need 1000+ of them on a single page. The reason is not so much Backbone's code is particularly inefficient but the fact that Backbone.View creates a separate a jQuery context in its constructor, and then delegates events in it, also using jQuery. Both are among the slowest parts of jQuery because they have to go thru Sizzle. So if you have 1000+ of Views, each creating a separate jQuery context of its own, you can easily run up to taking seconds to render a page on Mobile.

On Backgrid (my project), naively creating 1200+ view objects on a Macbook Pro on a 2.4gz i7 takes 700ms. It really does take seconds on mobile.

I'm in the process of getting rid of jQuery and coming up with a performant View class that works more or less like Backbone.View but uses the DOM API directly. Implementing event delegation with straight DOM methods have proven to be troublesome and unreliable so I might need to come up with a different way to attach event handlers on a DOM tree.

Backbone uses jQuery's event delegation, so there should've been minor differences between the two cases you describe, mostly with how listening to the Models/Collections worked.

Additionally, it sounds like you might've been binding a render to a change in the collection? In that case, you'd want to debounce the render or only start listening to changes after the view is actually rendered with data (say the parent only renders that view when it has the data for the 200 cards, then the subview listens for changes on the collection it's given).

Anecdotally, ~1000+ views can be performant in Backbone.

It's hard to say what bottlenecks you were hitting but zombie views that can't be GC'd, rendering to the page thousands of times (instead of to an in memory DOM element), or sorting your collections on dynamic, non-memoized values could have caused those kinds of slowdowns.

Were you using Marionette? It helped me increase performance a lot by cleaning up views properly and organize their rendering optimally. I almost can't imagine using Backbone without Marionette.

Did you use Backbone-relational for nested/related models? I've found that it has a significant performance penalty with lots of models.

I was also bothered by the fact that the two were instantiating very different objects, so I forked the tests and added a new case that uses Backbone's portable extend method to create vanilla objects: http://jsperf.com/backbone-vs-john-resig-class/5

TL;DR: the Backbone approach has similar performance characteristics compared to Resig's when instantiating similar objects. In some browsers (Firefox Nightly, Safari), Backbone's approach is significantly faster. It's also compatible with strict mode — although Backbone itself doesn't use strict mode — whereas Resig's uses arguments.callee which will throw errors.

Yes. This is precisely the problem. The inheritance model used by Backbone will be significantly more performant in terms of method calls, in general, because it doesn't implement a `super` concept. The construction should also favor Backbone's model since it doesn't create the function wrappers (in the non-trivial case, anyway).

Look at what Backbone's `extend` does: https://github.com/documentcloud/backbone/blob/master/backbo...

The subclass's constructor calls the parent's constructor function, just as in Resig's, however Resig's `Class` is:

    this.Class = function(){};

Whereas `Backbone.Model` looks like this: https://github.com/documentcloud/backbone/blob/master/backbo...

It's not hard to predict the outcome of this "benchmark."

Plus the fact that most performance issues come from DOM manipulation.

I don't know why, but on FF21, your approach is 9% slower than resig.