knockoutjs: Slow options bindingHandler

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/sugar/1.3.8/sugar.min.js"></script>
<form>
    <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>      <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select data-bind="options: items"></select><select data-bind="options: items"></select>   <select data-bind="options: items"></select>   <select...

JavaScript

var items = [];
for (var i=0; i<2055; ++i) {
    items.push(ko.observable(i))
}

var model = {
    items: ko.observableArray(items),
    toggleSign: function() {
        model.items().forEach(function(item) {
            item(-item());
        });
        return false;
    }
};

ko.applyBindings(model);