I trace some corruption when trying to export maximum number of assets.
Yes the Test Result and Bitmaps occupy large space. Also exporting and importing only the latest version could reduce the size and other headaches related to that.
Never try to export or import to an external device directly, try export to the current machine then move the file and while importing, move the file to the current machine where the TestPartner is installed then import. This would solve any other issues involved in networking or other issues related to external devices.
As no one could answer the capacity to export or import, I thought to start by letting all know the capacity that I could export safely. If any of the users have played with larger export then that could answer a bit to the query! Right?
I had successfully exported 7421 assets and the size of the XML file was 700 MB.
If you are interested to do some test, try increasing the RAM size and see if that helps! (I have 4 GB RAM)