Best bulk image download practise using curl?

Question

I have a script running for a Laravel 5.4 webapplication that is supposed to download a big amount of images (10k). I'm wondering what the best way to handle this would be. I currently grab the base64_encode() data from the remote image and write it to a local folder with the function file_put_contents(). This works fine but some images can take more than 10 seconds to download/write, image that times a 10 thousand. Fair enough these images are rather big but I would like to see this process happen faster and thus I am asking for advice!

My current process is like this;

1. I read a JSON file containing all the image links I have to download.
2. I convert the JSON data to an array with json_decode() and I loop through all the links with a foreach() loop and let curl handle the rest.

All the relevant parts of the code look like this:

<?php
// Defining the paths for easy access.
$__filePath     = public_path() . DIRECTORY_SEPARATOR . "importImages" . DIRECTORY_SEPARATOR . "images" . DIRECTORY_SEPARATOR . "downloadList.json";
$__imagePath    = public_path() . DIRECTORY_SEPARATOR . "importImages" . DIRECTORY_SEPARATOR . "images";

// Decode the json array into an array readable by PHP.
$this->imagesToDownloadList = json_decode(file_get_contents($__filePath));

// Let's loop through the image list and try to download
// all of the images that are present within the array.
foreach ($this->imagesToDownloadList as $IAN => $imageData) {
    $__imageGetContents = $this->curl_get_contents($imageData->url);
    $__imageBase64 =  ($__imageGetContents) ? base64_encode($__imageGetContents) : false;

    if( !file_put_contents($__imagePath . DIRECTORY_SEPARATOR . $imageData->filename, base64_decode($__imageBase64)) ) {
        return false;
    }

    return true;
}

And the curl_get_contents functions looks like this:

<?php
private function curl_get_contents($url)
{
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    $data = curl_exec($ch);
    curl_close($ch);

    return $data;
}

I hope someone could englighten me with possible improvements that I could apply on the current way I'm handling this mass-download.