GPU ram brand and Overclocking

So I noticed that my mining rig with two identical EVGA 3060TIs FTW3 have different ram brands. One is a Samsung and one is a Hynix.

I noticed that even though they have the same settings one is getting a better hashrate. 29 vs 27.5/28.

I have other EVGA 3070s with Samsung ram and they have great hashrate too (30). I have 3060TI XCs that run and Hynix and ive noticed I don’t get the same hashrates as others with their posted settings (26).

Do different ram types need different settings? Or is this just luck of the draw.