I'm upgrading my mining cards and swapping out from nvidia to AMD. I'm familiar with NVIDIA branding of performance on the cards e.g Ti , Founders Editions etc

What variant of AMD RX 480 would you recommend?
Really much difference in 4GB or 8GB?
Running the 480 on x4 PCI going to cause a performance issue? it hasn't with my NVIDIA cards.

I'm looking at getting a few of these and I heard 27-30mhash for Eth is what to expect

https://www.scan.co.uk/products/8gb-sapphire-radeon-rx-480-nitroplus-14nm-polaris-pcie-30-8000mhz-gddr5-1208mhz-gpu-1306mhz-boost-23

Or

https://www.scan.co.uk/products/nda-4gb-sapphire-radeon-rx-480-nitroplus-14nm-polaris-pcie-30-7000mhz-gddr5-1208mhz-gpu-1306mhz-boos


Thanks