Core and memory boost hash rate. But yes zec is more about core than mem, unlike say ethereum which is more about mem. Still Samsung makes the best ram on the market. Next would be micron, then hynix. Hynix is crap and you can’t overclock those cards much. I will wait until the announcement of the new cards. Frankly at 250us and falling it makes no sense to me to be buying any card at inflated prices. It makes more sense to buy the coin. 10xx series are end of life. There is no one that thinks the 20xx cards are not coming this year. At some point the market will be flooded with used 10xx. Probably toward the end of the year. A 1000us 1080ti could be selling for 500us in a few months. Certainly if they launch a 2080 at an msrp of 750ish which is very possible. The question is not if, but when they arrive.