Just a quick one, I'm building this rig at the moment and it'll have 4GB of ram... I read that's plenty enough for LTC mining but would a multi-coin switching pool like middlecoin require more ram for any reason? Haven't been able to find anything specific. I was under the impression Scrypt mining isn't ram intensive so it shouldn't matter?
I am not really sure if it was related to RAM, however when i compared my 2 mining rigs (same GPU's , same config, same cgminer version, same AMD CATA and SDK , different MoBo , different RAM) they get almost the same hash rate but the one with higher RAM hash a bit higher (5 - 8kh/s more and more stable) and have a lesser rejection and no hardware errors. On the rig with lower RAM, i get very few (not that noticeable) hardware errors (around 6HW and 10 rejected out of 1800 accepted shares).
EDIT: I am using Asus R9 280x DC2 TOP version 1, I am getting around 780kh/s for each card.