files over 100 in size is the max ammount you can do, any more files and it will fail.
You need to use windows explorer view on the document library to upload in big bulk ammounts!
similar answer here:
Cannot upload 600 multiple documents in document library
just to make it clear, 100 relates to the ammount of files you want to bulk upload. The max ammount of files you can bulk upload is 100 file. You cant change it as its hard set and not soft set. You need to use explorer view to migrate bulk files above 100!
as for the total file size, its all on central admin:
central admin -> application managment -> manage web applications -> select a web application you want to change -> within the tab above select general settings -> within the popup scroll down till you get to 'Maximum Upload Size'.
the default is 50MB, the max if i remember right is 2GB. Be it for one file or 500 files, it calculates it all as a combined ammount.
1) i set size limmit to 2GB, i have 90 files and totaling 1.5GB
that would upload fine as its under 100 files and the total combined size of 90 files is under 2GB.
2) i set size limmit to 2GB, i have 105 files and totaling 1.5GB
this will fail as it surpasses 100 file limit. The file size is still fine tho as its 1.5GB and max is 2GB. To get this working I would break the file ammount to two bulk uploads or use explorer view on the document library.
in your case your asking about uploading one file at 500mb within multiple upload form and you have set a max of 1GB upload limit.
as its a big single file have you set the web application web.config properly?
find and set it to this:
<httpRuntime executionTimeout="5600" maxRequestLength="901200" />
the above code is setting the upload limit for iis to 901.2 MB, giving the timeout a bit longer to execute due to the large upload aswell! set above accordingly (close to 500 mb mark)