I already have a 970 card, and I understand it is cheaper to buy another 970 card and run it in SLI which generally packs a marginal improvement over the gtx 980 ti alone. However I am unsure whether I should get a gtx 980 ti anyway, which gives me room to upgrade in the future whereas the gtx 970 SLI wouldn't. I would sell my gtx 970 card if i was buying a gtx 980 ti and the difference in price would not be too much of a problem, and I am even thinking of perhaps overclocking the gtx 980 ti for a 15% performance boost which in most circumstances would reach or beat the slight performance increase the gtx 970 SLI has over the gtx 980 ti. It may sound petty but I unsure about SLI I think mainly because I don't know much about it, is it a reliable upgrade? I know the general policy og the more moving parts the higher the rate of failure, but wold SLI really be worth the extra cash? If possible do any of you have any sources for reliable and informative facts about SLI and how it operates, almost a guide to it? Many thanks guys, Tom