Optimization db queries - scaling big data - Laravel 5 - php

Question

I've been working on a web-app that uses Laravel 5. It's running on localhost (xampp) on a windows 8.1 PC. 4GB RAM, 2,67GHz processor, pretty simple.
The table I'm querying most of the times contains a lot of rows (10.000 give or take) - so many that to write a route that does:
return User::all();
Running this just returns a white screen. Sometimes Chrome console lists a 500 (Internal Server error).
Echoes or prints made before the query are shown but nothing after that is executed. Querying another model (whose table only has 2 rows) returns the data correctly.
Which leads me to conclude that my server isn't scaling well for this amount of data. I'm trying to fix this by doing.
User::all()->chunk(200, function($chunkOfTickets){ /*some code*/});
which I expected would split the data into chunks to make it easier on the server. This doesn't work, however, because Eloquent is first fetching all the data (and breaking because it can't handle it) and only then dividing it into chunks.
Thanks for reading.
EDIT: just tested over and over, requesting increasingly greater ammounts of data. The limit is 26000 rows approximately (27000 and out of memory error is returned).
As stated in the comments the php log states this. Apparently I was requesting so much memory it crashed before Laravel could show the error message
[01-Jul-2015 17:27:51 UTC] PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 8376445 bytes) in C:\xampp\htdocs\gamescaffold\vendor\laravel\framework\src\Illuminate\Support\Collection.php on line 791
Extra Edit
Is there a way I can divide in chunks the reply from the DB? like:
User::chunk(200)->all(); /*which obviously does not work*/
If I write a seemingly complex query to the database directly through phpMyAdmin it's returning 37035 rows in 0.0045 seconds. (I suspect there's some under the hood optimizations here by xampp or something though)

Answer 1

Note: I'm posting this as an answer because it involves some code. I guess I've totally missed your point in the original question because I though that you were trying to return the whole result set to the client. If I'm still missing something, please leave a comment and I'll delete this answer.
So I want to take a set of objects, do stuff with them and save them back to the DB
That's an easy one!
$chunkSize = 100; // or whatever your memory allows
$totalUsers = User::count();
$chunks = floor($totalUsers / $chunkSize);
for ($chunk = 0; $chunk <= $chunks; $chunk++) {
$offset = $chunk * $chunkSize;
$users = User::skip($offset)->take($chunkSize)->get();
foreach($users as $user)
{
// do something
$user->save();
}
}
If it takes too long, you'll probably get a timeout if you trigger this loop from HTTP, so you should probably run it from console.

Answer 2

DB::table("table")
->select('column1', 'column2')
->orderBy('column2', 'asc')
->chunk(70000, function($users) {
foreach ($users as $row) {
// To do with data
}
}