File upload restrictions per browser and environment

I am looking for the restrictions on file upload sizes per browser and environment to try and find my bottleneck. I've been told it's 2 gigs but I don't know where/what the limiting factor is. Specifically, I'm looking for the max size for 开发者_如何学JAVAeach of the below:

• Firefox
• IE
• Chrome
• IIS 6
• IIS 7.5
• ASP.NET 4.0

Note: We are using native browser upload; no flash, java, or the like

---

I would imaging the "2 gig limit" mentioned is a result of 32-bit integers (read: most 32-bit programs/servers) used throughout the various infrastructure -- it's only relatively recently that 64-bit file access has made it into consumer operating systems. (In addition to the above end-points, any intermediate proxies as well as file-systems, etc, must also be considered as limiting factors).

I can't find anywhere in RFC 2616 that actually sets the "upper limit" for things such as Content-Length though.

Edit (my thoughts): If it's a captive audience, perhaps use an alternative (e.g. Flash/Silverlight/ActiveX/etc) agent for the uploads?

---

in asp.net web.config find tag <httpRuntime > or if it is not there add

<httpRuntime maxRequestLength="...." ....

maxRequestLength limits how much is the request size. I think max value that can be set is 2G.