Asynchronous writing and reading of data to a storage

I would like to write and read data asynchronous to/from a storage (>1GB required). Connecting a SD-Card directly to the interface of my FEZ Mini causes blocking all threads for a couple of hundred milliseconds.
Gus already told me that I cant expect real time from netmf. But despite from the storage thing the real time capability is sufficient for my application (
Has someone an idea for an alternative solution?

I know that Wouter did some RLP coding with SD cards. Check this old thread may be it will give you some inspiration on how to approach your issue: