hey how is the hashrate for the RX 480 when overclocked and modded the bios?
That is around 300H/s.
When I was mining ZEC with my Sapphire Nitro+ OC 8GB 480s I was getting 330H/s on them with some fairly heavy OC.
Does the amount of ram make much difference with ZEC and ETH? 4GB versus 8GB
Not as much as speed of the memory. Some of Sapphire's 4GB cards have slower mem while the 8GB Nitro's have faster Samsung memory. I have a friend who bought MSI Armor 4GB 480s and with a BIOS mod he was able to get 28MH/s out of them as opposed to 29/30MH/s with the Sapphire Nitro+ 8GB cards. So in short not much of a difference.