Question i7-8700k vs i7-9700k specifically for VR

[rookiebuilder82]

I'm having a tough time deciding between the 8700k and 9700k when building a system for VR. I know it's bound to have minimal difference and GPU is far more important but it's still running my head through a loop. My thought process is the 8700k would be more practical considering it has 6 multithreaded cores to handle more process as opposed to 8 single threaded cores.

This is also not a budget question, considering they're only $30 apart. I'll also be utilizing the RTX 2070 for my GPU (unless I can win a bid on a GTX 1080 Ti on ebay for the same price).

I guess I have two questions: 1. When would 8 single threaded cores out perform 6 multithreaded cores (and vice-versa) (also just in general, as I'm trying to understand this the best I can) and 2. In your personal opinion, which do you think would provide a smoother VR experience?

 

[Supernova1138]

Generally speaking 8 cores with no HT is slightly better than 6 cores with HT, but there are some non-gaming applications where this isn't necessarily the case. Tile based rendering in something like Blender is heavily dependent on thread count and uses hyperthreading very effectively to the point where the 8700k can eke out a slight win over the 9700k despite having fewer cores. Realistically speaking as things are right now, the 9700k is slightly better for gaming. It's possible that future games may start leveraging more threads and using HT heavily, and maybe at some point in the future the 8700k might pull slightly ahead or offer slightly more consistent performance in future games that can leverage 12 threads, but that's not certain and won't happen for several years either way. When it comes to VR either CPU should be able to consistently get you 90+FPS so long as your GPU can keep up.

 

[rookiebuilder82]

Generally speaking 8 cores with no HT is slightly better than 6 cores with HT, but there are some non-gaming applications where this isn't necessarily the case. Tile based rendering in something like Blender is heavily dependent on thread count and uses hyperthreading very effectively to the point where the 8700k can eke out a slight win over the 9700k despite having fewer cores. Realistically speaking as things are right now, the 9700k is slightly better for gaming. It's possible that future games may start leveraging more threads and using HT heavily, and maybe at some point in the future the 8700k might pull slightly ahead or offer slightly more consistent performance in future games that can leverage 12 threads, but that's not certain and won't happen for several years either way. When it comes to VR either CPU should be able to consistently get you 90+FPS so long as your GPU can keep up.

But are there VR specific games that are thread dependent? How do I found out which games will work better with 6 multithreaded cores if benchmarks aren't available for the processors in question?

 

[Supernova1138]

Generally speaking 8 cores with no HT is slightly better than 6 cores with HT, but there are some non-gaming applications where this isn't necessarily the case. Tile based rendering in something like Blender is heavily dependent on thread count and uses hyperthreading very effectively to the point where the 8700k can eke out a slight win over the 9700k despite having fewer cores. Realistically speaking as things are right now, the 9700k is slightly better for gaming. It's possible that future games may start leveraging more threads and using HT heavily, and maybe at some point in the future the 8700k might pull slightly ahead or offer slightly more consistent performance in future games that can leverage 12 threads, but that's not certain and won't happen for several years either way. When it comes to VR either CPU should be able to consistently get you 90+FPS so long as your GPU can keep up.

But are there VR specific games that are thread dependent? How do I found out which games will work better with 6 multithreaded cores if benchmarks aren't available for the processors in question?

Right now there are virtually no games out VR or non-VR that scales well enough across 12 threads to make the 8700k a better gaming CPU. Performance is still close either way because most game engines aren't scaling all that well across huge numbers of threads and quite often performance is limited by draw calls, which on DX11 games is still being handled by a single thread. Proper DX12 or Vulkan support might change that, but very few titles are using these newer APIs in any real way.

Ultimately it doesn't matter too much which of the two CPUs you get, if you are overclocking and run both at the same clockspeed then gaming performance is extremely close with the 9700k maybe only eking out something like a 2-5% lead, and that's running at 1080p with an RTX 2080Ti. If you are getting an RTX 2070 you're going to be even more GPU bound and there would likely be no appreciable difference.