How to speed up the execution of this PHP script

How to speed up the execution of this PHP script

I have write a script for webscraping where i am fetching each link from
the page and getting load that url in the code and this working extremely
slow this is taking about 50 sec for first output and taking an age to
complete about 100 links, I am not getting why this is working so slow, I
am thinking about caching but don't know how this could help us.

1) Page caching OR Opcode cache.

code is :
public function searchForum(){
global $wpdb;
$sUrl = $this->getSearchUrl();
$this->logToCrawler();
$cid = $this->getCrawlId();
$html = file_get_dom($sUrl);
$c=1;
foreach($html('div.gridBlobTitle a:first-child') as $element){
$post_page = file_get_dom($element->href);
$post_meta = array();
foreach($post_page('table#mytable img:first-child') as $img){
if(isset($img->src)){
$post_meta['image_main'] = self::$forumurl.$img->src;
}
else{
$post_meta['image_main']=NULL;
}
}
foreach($post_page('table.preferences td:odd') as $elm){
$post_meta[] = strip_tags($elm->getInnerText());
unset($elm);
}
/*Check if can call getPlainText for description fetch*/
$object = $post_page('td.collection',2);
$methodVariable = array($object, 'getPlainText');
if(is_callable($methodVariable, true, $callable_name)){
$post_meta['description'] =
utf8_encode($object->getPlainText());
}
else{
$post_meta['description'] = NULL;
}
$methodVariable = array($object, 'getInnerText');
if(is_callable($methodVariable, true, $callable_name)){
/*Get all the images we found*/
$rough_html = $object->getInnerText();
preg_match_all("/<img .*?(?=src)src=\"([^\"]+)\"/si",
$rough_html, $matches);
$images = array_map('self::addUrlToItems',$matches[1]);
$images = json_encode($images);
}
if($post_meta[8]=='WTB: Want To Buy'){
$status='buy';
}
else{
$status='sell';
}
$lastdate = strtotime(date('Y-m-d',strtotime("-1 month")));
$listdate = strtotime(date('Y-m-d',strtotime($post_meta[9])));
/*Check for date*/
if($listdate>=$lastdate){
$wpdb->query("INSERT
INTO tbl_scrubed_data SET
keywords='".esc_sql($this->getForumSettings()->search_meta)."',
url_to_post='".esc_sql($element->href)."',
description='".esc_sql($post_meta['description'])."',
date_captured=now(),crawl_id='".$cid."',
image_main='".esc_sql($post_meta['image_main'])."',
images='".esc_sql($images)."',brand='".esc_sql($post_meta[0])."',
series='".esc_sql($post_meta[1])."',model='".esc_sql($post_meta[2])."',
watch_condition='".esc_sql($post_meta[3])."',box='".esc_sql($post_meta[4])."',
papers='".esc_sql($post_meta[5])."',year='".esc_sql($post_meta[6])."',case_size='".esc_sql($post_meta[7])."',status='".esc_sql($post_meta[8])."',listed='".esc_sql($post_meta[9])."',
asking_price='".esc_sql($post_meta[10])."',retail_price='".esc_sql($post_meta[11])."',payment_info='".esc_sql($post_meta[12])."',forum_id='".$this->getForumSettings()->ID."'");
unset($element,$post_page,$images);
} /*END: Check for date*/
}
$c++;
}
Note :
1) I am using [Ganon DOM Parser][1] for parsing the HTML.[1]:
https://code.google.com/p/ganon/wiki/AccesElements
2) On winddows XP with WAMP, Mysql 5.5 PHP 5.3, ! GB of RAM.
If you need more info please comment them.
Thanks