AnandTech benchmarked the new RTX graphics cards, and concludes:
So where does that leave things? For traditional performance, both RTX cards line up with current NVIDIA offerings, giving a straightforward point-of-reference for gamers. The observed performance delta between the RTX 2080 Founders Edition and GTX 1080 Ti Founders Edition is at a level achievable by the Titan Xp or overclocked custom GTX 1080 Ti’s. Meanwhile, NVIDIA mentioned that the RTX 2080 Ti should be equal to or faster than the Titan V, and while we currently do not have the card on hand to confirm this, the performance difference from when we did review that card is in-line with NVIDIA’s statements.
The easier takeaway is that these cards would not be a good buy for GTX 1080 Ti owners, as the RTX 2080 would be a sidegrade and the RTX 2080 Ti would be offering 37% more performance for $1200, a performance difference akin upgrading to a GTX 1080 Ti from a GTX 1080. For prospective buyers in general, it largely depends on how long the GTX 1080 Ti will be on shelves, because as it stands, the RTX 2080 is around $90 more expensive and less likely to be in stock. Looking to the RTX 2080 Ti, diminishing returns start to kick in, where paying 43% or 50% more gets you 27-28% more performance.
Neither of the two new RTX cards seem to be particularly smart purchases at this point – the 2080 barely performs any better than a 1080 Ti, and while the 2080 Ti does offer a decent performance improvement over the 1080 Ti, it’s also $1200. You might want to wait to see if NVIDIA’s raytracing efforts pay off and gets adopted in video games, and if said raytracing features don’t suck too much performance.