[bpat1434]

You can upload as much as you want. PHP ships with a very restrictive 2M upload limit though. Unless you edit this setting and raise to to be something like 32M, there will be a PHP error. If display_errors is off, you won't see anything

Just be careful when you upload large files. If your internet connection goes in waves of speed (i.e. high speed for a few seconds, then trickles to a crawl, then back to a high speed, then trickle, etc.), you might have a hard time uploading large files.