Whenever you send coins, it sends all the coins in the input/s given, sending your change to a new address. The point of this is so that an attacker cannot re-broadcast a valid transaction extra times to cause it to be executed multiple times, emptying an address. As the input is one particular output, and it is fully consumed when spent, any attempts to re-broadcast would only be referring to no longer redeemable inputs, and would be rejected.
What would you suggest running on a 7970?
core clock between 1050 and 1150, mem clock 1250, 256 worksize, -g 2, --lookup-gap 2, intensity 13 will get you running around 2.1Mh/s completely stable.
Thank you for that! Can I ask another stupid question? LOL, I wonder who creates the c addresses. The wallet that creates the transaction? Is it from another "set of 100" addresses your wallet always has at the ready? I mean, the usual addresses always start with an X, no? These start with a c?