如何使用eloquent进行批量数据库更新

Question

I would like to improve the following code to insert 1000 records at once rather than within the chunked loop.

public function fire()
{
    $self = $this;
    $time = date('Y-m-d H:i:s');
    $this->info('Starting chunk: '.$time);

    Item::chunk(1000, function($items) use ($self)
    {
        foreach ($items as $item)
        {

            $sizeInBytes = $self->getCurlHeaders($item->bigimg);
            $item->imgsize = (string) $sizeInBytes;
            $item->save();
        }
        $time = date('Y-m-d H:i:s');
        $self->info('Ending chunk: '.$time);
        exit;
    });
}

How can I do that with the Eloquent ORM and Laravel? The code is running as an artisan task. The target table has ~1000000 rows.