Upgrading my 3570k. Help :)

[gearsplayer]

So I may be upgrading my [email protected] as it's starting to show it's age in terms of multi tasking.

I currently have a dual monitor setup with my main monitor being a 240hz, although I'm more than happy with 144 fps gaming, due to the fact i only got that 240hz because it was on sale.

The GPU i have is the gtx 980 which has a pretty hefty OC (+200 on the core and +400 on the mem)

Some extra info.

1)Depending on the performance of the upcoming 1180 I may take the leap to 4k gaming.

2) I tend to only upgrade my CPUs every 5 years although this partly due to there being no upgrade path on intel mobos

3) I play all sorts of games such as guild wars 2, wow, far cry, the witcher, overwatch est. While i play these games i tend to have quite a few tabs open on my other screen and maybe a stream/yt vids playing.

4) I AM NOT a pro mlg csgo, overwatch or whatever fps game there are these days, BUT i do like a smooth experience when I play my games.

So what should i go for, the 2600x, 2700x, 8600k or the 8700k? I have a h105 and I will be overclocking the chips as far i can push them within safe temp+ voltages

 

[gearsplayer]

I have good old i5-2500k and I will prolly upgrade to new 2700x build this year. Best all around CPU atm imo.

Thanks for the advice .

In terms of gaming performance how much of an increase should i see taking multi tasking out of the equation?