当使用phonegap在jquery mobile中加载大型xml文件时，如何减少加载时间

Question

I'm on creating jquery mobile app in phonegap 0.9.6.
intend to create array type of json object after loading xml data
like this '[{"a":"val01", "b":"val02"}, {"a":"val03", "b":"val04"}, ...]'.
a, b are column name.

but taking a so long time(14 secs) in case of loading large size xml data.

 - first xml - size : 1.45MB, time : 13.54s (4013 rows, 11 columns)
 - second xml - size : 827.15KB, time : 59ms (3128 rows, 6 columns)

first xml is just below double size of second xml.
but loading time is not double.

I don't know why loading first xml takes so long time.
So I need your help and advice.
thanks.

---

代码示例 - 使用一个xml文件创建一个数组。

function CreateObj() {
var arr = [];
var colCnt = $(inputXML).find('RECORD').first().children().length; //column length
//loop rows count
$(inputXML).find('RECORD').each(function() {
    var row = {};
    for (var i = 0; i < colCnt; i++) {
        row[columnName] = Trim(columnValue);
    }
    arr.push(row);
});
return arr; }

---

function LoadXMLData(file) {    
$.ajax({
    type: "GET",
    url: "data/" + file + ".xml",
    dataType: "xml",
    async: true,
    error: function(xhr, status, err) {
        var errMsg = (err) ? xhr + "\n" + status + ":" + err : "";
        navigator.notification.alert(errMsg + "\nData not loaded. Retry This App", onAlert);
    },
    success: function(data, status, xhr) {
        xmlDocs[file] = CreateObj();
    }
});  }