如果您不需要同步请求,请考虑使用curl_multi_ *函数(例如curl_multi_init,curl_multi_exec等),这也提供了很大的性能提升.

更新：

我尝试使用一个新的句柄为每个请求和使用相同的句柄与以下代码：

ob_start(); //Trying to avoid setting as many curl options as possible
$start_time = microtime(true);
for ($i = 0; $i < 100; ++$i) {
    $rand = rand();
    $ch = curl_init();
    curl_setopt($ch,CURLOPT_URL,"http://www.google.com/?rand=" . $rand);
    curl_exec($ch);
    curl_close($ch);
}
$end_time = microtime(true);
ob_end_clean();
echo 'Curl without handle reuse: ' . ($end_time - $start_time) . '<br>';

ob_start(); //Trying to avoid setting as many curl options as possible
$start_time = microtime(true);
$ch = curl_init();
for ($i = 0; $i < 100; ++$i) {
    $rand = rand();
    curl_setopt($ch,"http://www.google.com/?rand=" . $rand);
    curl_exec($ch);
}
curl_close($ch);
$end_time = microtime(true);
ob_end_clean();
echo 'Curl with handle reuse: ' . ($end_time - $start_time) . '<br>';

并得到以下结果：

Curl without handle reuse: 8.5690529346466
Curl with handle reuse: 5.3703031539917

因此,重复使用相同的句柄时,实际上可以在多次连接到同一台服务器时提供显着的性能提升.我尝试连接到不同的服务器：

$url_arr = array(
    'http://www.google.com/','http://www.bing.com/','http://www.yahoo.com/','http://www.slashdot.org/','http://www.stackoverflow.com/','http://github.com/','http://www.harvard.edu/','http://www.gamefaqs.com/','http://www.mangaupdates.com/','http://www.cnn.com/'
);
ob_start(); //Trying to avoid setting as many curl options as possible
$start_time = microtime(true);
foreach ($url_arr as $url) {
    $ch = curl_init();
    curl_setopt($ch,$url);
    curl_exec($ch);
    curl_close($ch);
}
$end_time = microtime(true);
ob_end_clean();
echo 'Curl without handle reuse: ' . ($end_time - $start_time) . '<br>';

ob_start(); //Trying to avoid setting as many curl options as possible
$start_time = microtime(true);
$ch = curl_init();
foreach ($url_arr as $url) {
    curl_setopt($ch,$url);
    curl_exec($ch);
}
curl_close($ch);
$end_time = microtime(true);
ob_end_clean();
echo 'Curl with handle reuse: ' . ($end_time - $start_time) . '<br>';

并得到以下结果：

Curl without handle reuse: 3.7672290802002
Curl with handle reuse: 3.0146431922913

表现仍然相当显着.