I found that using a external drive gave me latencys problem too so i changed back to my computers hard drive , iam not sure of the specs of that external drive but all i use it for now is to back up
I did some research on my computers hard drive and found its below specs [5100rpm] which is pritty standard for a laptop so iam told. so now i'am thinking that the load between bfd2 and reaper at the same time is causing the performance issue.
I'am also looking into a upgrade to a raptor hard drive which spins at 10000rpm and has 32mg cache.
Iam am still working on this to see if it is compatable with my computer.
Iam also going to post a thread on reaper's forum to see if any other reaper users are having the same problem.
Join into that one and we will see if its a problem in reaper.