Using the least RAM with curl_exec

Could you please tell me which code samples uses the least RAM? Here are my two examples:

$ch = curl_init();

foreach ($URLS as $u开发者_如何学JAVArl){
    // set URL and other appropriate options
    curl_setopt($ch, CURLOPT_URL, $url.'&no_cache');
    curl_setopt($ch, CURLOPT_HEADER, 0);

    // grab URL and pass it to the browser
    curl_exec($ch);
}
// close cURL resource, and free up system resources
curl_close($ch);

or

foreach ($URLS as $url){
     $ch = curl_init();
    // set URL and other appropriate options
    curl_setopt($ch, CURLOPT_URL, $url.'&no_cache');
    curl_setopt($ch, CURLOPT_HEADER, 0);

    // grab URL and pass it to the browser
    curl_exec($ch);
            curl_close($ch);
}
// close cURL resource, and free up system resources

---

First one has lighter overhead, as you only instantiate the curl object once, but if curl has any leaks in it, and you're fetching a large-ish number of URLs, you could run out of memory.

Usually I only invoke a new curl object if the next url to fetch has too many differences in settings than the old curl. Easier to start with a default setup and make changes from that than try to "undo" the conflicting settings from the previous run.