You will be fine with contours and topology, but I suspect you will have trouble with the water simulation. The sandbox water is a simulation not a representation i.e. it is calculating the behavior of the water not just showing something that look right’ish. The water simulation is most affected by the number of parallel calculations that can be done and this roughly equates to the number of cores on the graphics hardware the 1030 has 384 cuda cores and will work, but it is likely to go slow when things get busy. You can turn the water off if you don’t want it and get away with a much lower spec of graphics hardware. I run a GTX980Ti (2816 cuda cores) which works well, but you can still see it slow when you get a lot of water. The 980 is an older card (superseded by the 1k (980ti is roughly on a par with 1070) and 2k ranges) so does not have the some of the newer features but gamers’ are now feeling behind the curve so are upgrading so the older cards can be obtained second hand for a sensible price. Obviously second hand has risk associated with it, but it all comes down to budget, risk, value, other uses you have for the card. You can make your own choice about where you sit with balancing these.
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