Hello, please can i give Sli on 980Ti and TitanX? so both cards work? Or if i want use Sli i must have the same card? The cards have same packaging: https://www.czc.cz/evga-geforce-gtx-980-ti-6gb-gddr5/172950/produkt https://www.czc.cz/evga-gtx-titan-x-sc/169222/produkt