Does uploading size from a silverlight module depend upon the RAM size ?

Question

I have a Silverlight module that is uploading few images on the server. I am able to upload an image of size upto 4 Mb from a machine which is having >2GB RAM. But if the same solution is run on a 1 GB machine the image does not get uploaded. I have added the following node in the web.config <httpRuntime executionTimeout="900" maxRequestLength="8096" /> I am converting the image into stream of bytes at the silverlight end and then sending it to the webservice. Does uploading depend upon the RAM??