[mythtv-users] Is 4GB RAM overkill for mythtv?

[Captain Krypto]

I am setting up a new FE/BE myth box and accidentally ordered two 2GB pairs
of RAM.  I was going to send one of the pairs back, but though I might get
better performance if I put all 4GB of RAM into the box.  It is a dual-core
64-bit system so addressing the RAM won't be a problem.  Besides the usual
mythtv functions, I plan to use the box for the following tasks:

-archiving (re-encoding) recorded programs in both SD and HD
-viewing HD recording
-serving a diskless frontend
-suspend to RAM

Would mythtv use all of the RAM?  Would more RAM speed up re-encoding of
programs?  Would more RAM be beneficial to commercial flagging?