Dimdes23 :
Is Gtx 1060 3gb good for games at 1080p with low settings? will be paired with i5 6400 and 8gb ram
I have a GTX 1060 6GB and it is perfectly fine for 1080p on ultra settings for most games. I think you'll be fine. If you're worried about bottlenecking, you can go by what this site says (http://thebottlenecker.com/bottleneck-calculator/ ) but I really don't think you're going to be bottlenecking it at all. This website says that my I7 6700k will bottleneck it 6% and ironically it also says that if I had a GTX 1080 instead of my GTX 1060 I would only bottleneck it 6%. I'm assuming it has a +-6% margin of error in its calculations or something and that it will never have a 0% bottleneck.
I was in your same situation when purchasing mine GTX 1060, I was torn to spend the extra $50 or so to get 2x more VRAM myself, but I decided to go all out with it. The way I see it, I'd rather have something I'm happy with instead of something I wish I spent the extra money earlier and got.
I can't speak on behalf of the 3GB's performance, however, I really do think you'd be happy with a GTX 1060 if you're just going to be playing at 1080p.
Also, look up what games you want to play and see if they are demanding on VRAM, that should be the easiest way to determine if you should get the 6GB or 3GB.
As for RAM, getting more doesn't mean faster. I have 16GB personally and I don't think I go over 8GB very often. Currently, I have League of Legends open (only at the menu, not in game), seven Chrome tabs open, Task Manager, and 79 background processes open and I am using 4.7GB of my RAM (on Windows 10 64bit).
I don't know what you're using for storage, but I highly recommend getting an SSD. You'll see massive performance increases in map loading times and just opening programs in general. I went for a 240GB SSD and a 1TB HDD in my build and I put all of my programs, files, and my OS on the SSD whereas my games are on my HDD. Some games I play frequently I have on my SSD just to improve loading times but ones that I don't play a lot or that take up a boat load of space I install them onto my HDD.
Good luck man! If you have any questions on what my 1060's performance is in specific games I own, you can PM me. I found that my 1060 doesn't exactly live up to the benchmarks that people have gotten for the card, although mine is only an EVGA Superclocked one, there are ones with higher clock speeds and minor changes that do add to the performance of the card.