Hi, there's something very wrong with your results.  You have GTX 1080ti faster than RTX 2080, when it's actually the other way around, the RTX 2080 has been shown on many review sites to be significantly faster than the GTX 1080ti.  But here in your article you have the GTX 1080ti being significantly faster than the RTX 2080 - there's something very wrong with your results here, there's something going on that's not right, I think you should look into it & re-publish the results - your performance results shown here are not valid & are misleading.

The RTX 2080 is often faster than a GTX 1080 Ti. This is also clear from the benchmarks. However, the testplatform should also be considered. The GTX 1080 Ti was then tested with an Intel system.
Synthetic benchmarks should not be used as a match for gaming performance.

Sebastian, that is not a valid point, there were no GTX 1080ti gaming results included in your charts in that article, you only included the GTX 1080ti in the synthetic benchmark charts.  Also, if your Ryzen platform has such an influence on the results, which would be a negative influence - Ryzen games at less fps than Intel, then I don't know how you compare different GPUs if they're in different base systems - that's an oversight, a mistake/inaccuracy in the methodology that invalidates your numbers presented in your article.  You should have used the same base system to compare graphics cards, it makes your article invalid.

Probably worth re-doing the testing with the same platform.

Thanks for adding the i9-9900K system synthetic benchmarks, "something is not very wrong" now.  This now shows the RTX 2080 to be faster than the GTX 1080ti in most of the synthetic benchmarks, rather than being slower (which is what was seen in the Ryzen system before you included the i9-9900K system results).

There is a significant difference between the results of the Ryzen & Intel systems, anything from 5-14% depending on the benchmark chosen, as seen in your charts.  If you had done the gaming benchmarks side by side with the Ryzen system you would have seen even bigger differences, with  the large differences being seen at lower resolutions and higher fps ranges - the Intel system would extend it's lead here.

I just mention these points because choice of base system will significantly influence your results of how the RTX 2080 compares against other cards you have tested in the past, that's why it's good to have the same base system being tested across the cards.  Yes, you have to move with the times and update the system every several years to keep it relevant, but testing as much on the same base system as possible is gonna show the most comparable results between graphics cards.  Thanks for adding the i9-9900K system results as this helps to bring a better comparison to your previous graphics cards tested - the Ryzen system is just too different from your previous Intel systems you've used for testing.