I'm stuck trying to decide between the two platforms. I have about 1K to spend so the price performance is not at the top of my list of considerations. However saving money is not a bad thing and going the AMD route is about £250 - £300 cheaper, depending on if I want to gamble on getting Samsung b-die memory that should fit under my large air cooler.
The confusing be it, looking at the benchmarks from different sites they seem to be all over the place. In some the 7820x hammers the 1700 whilst in others the 1700 is giving similar performance to the 7820x. Then there are the platform issues with x299 counterbalanced be the 1700 having no guarantee that it will reach to the magic 4GHz (having had a look around on various forums it seems a lot of the newer one are capping out at around 3.8) is making me hesitant to want to jump in with either one. All the while I'm sat with a 3570k getting increasingly ****** off with the CPU induced FPS drops in BF1.
Welcome on my boat two months ago. I was getting increasingly obsessed with Ryzen vs 7700k vs 7820x benchmarks. There is not hiding that 7700k gives the highest gaming performance on the market right now unless you do stuff like recording your gaming for Youtube / streaming in the background. If you use your PC exclusively for gaming I would either go for 7700k or Ryzen 1600 to save some cost.
If for some reason you need multicore performance whatever for virtualisation (Vmware/VirtualPC etc.), rendering or streaming gameplay I would consider AMD Ryzen 7 and Intel 7820x. 7820x will offer slightly better performance over Ryzen in majority of cases and much better in some edge cases. There are games which simply prefer single core performance over anything else. The worst case scenarios I have heard about are games like Arma 3 or GTA V. Both poorly optimised, but also both demanding a lot from the CPU in terms of what needs to be displayed on the screen in the same time.
The question is how much you care about squeezing as much frames as possible from the games you play. Please understand that Ryzen won't deliver a sub standard gaming performance, it simply won't be as good as 7700k, depending on a game anywhere between 10 % to 25 % behind in those edge cases.
I like the idea of an 8 core CPU as it offers me the flexibility I need and the future ability to upgrade to 7nm Zen2 and Zen3 using the same motherboard is a nice bonus for me. Also I didn't mind that free gaming chair coming from OCUK with Ryzen 1700x and 1800x
Consider also that many of those benchmarks use 7700k OC'ed up to 5 GHz, if you really want to stick to air cooling, you will see even smaller advantage over Ryzen. You probably want to confirm that with others, but at those frequencies a lot of 7700k need watercooling or even deliding to deal with the extra heat. On other hand from what I understand Ryzen can easily be OC'ed to approx. 4 GHz and cooled with the best air cooling options out there or mainstream AIOs while maintaining reasonable temps around 70 C.
I'm afraid that this is a decision you will have to make by yourself and suffer from a potential buyer's regret. I would watch the benchmarks I have linked. Consider the games you usually play an try to find some hard data from multiple sources before you make the final decision. I would also consider stuff like what FPS and resolution you play at and what GPU you want to pair your CPU with. If you are crazy at 144 Hz 1080p gaming, 7700k might be the best option. If you don't mind dipping under 144 FPS in titles which rely on high IPC consider Ryzen5/7.