My 570 4Gb are better than my 570 8Gb, is it normal ?
Same core but higher memory frequency on 8Gb.
2.3-2.4MHs on 4Gb
1.9-2.1MHs on 8Gb
256x0 on both. Tried 384x0 on 8Gb, very few change on hashrate.

EDIT : well, it seems I have big differences between my differents x70 4Gb, and my first test was on my bests ...