I'm planning to create a new rig with few GPUs.
I can get some decent price for XFX Radeon RX 480. I'm pretty sure that this has been asked a few times, but I couldn't remember:
Should I purchase XFX Radeon RX 480 4GB or 8GB? Will the memory affect hashrate?
For the ZCash mining, the memory speed is very important. So you have to increase the clock or change the timing.