What gtx 770 do u have is it the EGVA? Would you recommend changing my card for it? Does it make ETS unplayable ??
Mine is a EVGA.
Will i recommend changing your card to a 770? well, not if it costs more. They are very equal. Some games run a little better on the 770 and some other run a little better on the R9-280x
About the Ultra setting lag, Maybe it's a software issue with Nvidia and a specific graphic setting. It may be the guys making truck simulator's fault or it could be due to a Nvidia driver problems.
---------- Post added at 10:20 PM ---------- Previous post was at 10:16 PM ----------
take a look at this article.
You can see the R9-280X and the 770 as well as other cards go head to head in gaming benchmarks. Don't look at the green mark. It's an overclocked version. the other cards are all stuck.
You can see how close the 2 cards are
http://www.techpowerup.com/reviews/Gigabyte/R9_280X_OC/6.html