Memory connection (R)

I have to serialize (large) R objects many times. To avoid re-collecting garbage from the received raw vectors (after profiling, it turns out that half of my script time is spent on gc!) Id like to request R for direct writing to the memory buffer - always the same as after each serialization identifier, call function C with .C, which will work directly in this memory buffer; this is the result of this C function that interests me.

Is it possible? How unreasonable is this?

Thanks in advance.