Low latency performance comparison of the i7-6850k, Ryzen 1800x, and i7-7700k
 
6850k - six cores @ 4GHz
1800x - eight cores @ 4GHz
7700k - four cores @ 4.5GHz
 
Audio Interface:
RME Fireface UFX at a 48-sample ASIO buffer size 44.1k
 
Audio Stress Test
Running DAW Bench (Reaper version of the test with its multi-band compressor for load)... here are the maximum instances that each CPU could run completely glitch-free:

• 6850k - 223 instances of the multi-band compressor (CPU load with transport running was 99%)
• 7700k - 180 instances of the multi-band compressor (CPU load with transport running was 95%)
• 1800x - 170 instances of the multi-band compressor (CPU load with transport running was 93%)

 
Generic Benchmarks
Floating Point Math

• 1800x - 16126
• 6850k - 12212
• 7700k - 8816

Integer Math

• 1800x - 43898
• 6850k - 29468
• 7700k - 21921

Single Thread

• 7700k - 2641
• 6850k - 2335
• 1800x - 2104

 
If you just look at the generic CPU benchmarks, you'd expect the 1800x to smoke the 6850k.
This is why audio specific low-latency stress-testing is important.
 
For low-latency audio work, the i7-7700k ($300) is outperforming the 1800x ($500).
That kills the impetus to use the 1800x.
For working with heavy loads at low-latency, the i7-6850k ($500) is the best of the three.
 

<sigh>
 
I just bought an i7-6700 and I already feel inadequate 

7700k is but a small notch faster than the 6700k.
Cost difference is about $30... and that's about commensurate with the performance gain.  

BobF
<sigh>
 
I just bought an i7-6700 and I already feel inadequate 

My i7 4790 still works for me.  So does my FX6300.

Not suggesting everyone run out an buy a new CPU.  
 
There's just been a lot of interest with the Ryzen CPUs being recently released.
Lots of hype about their performance.
It's important to know the details.

Just joking around, Jim.  I appreciate all of the info you post 'round these parts. 

I recently (December) built an i7 6700K system.  It should last me for many years.  I don't feel "inadequate".  its a 6700K but I don't really plan on overclocking it, happened to get the 6700K model for the price of the 6700. 

It would be interesting to find out why the 1800x system glitches at a lower CPU %. DPC compared with the 6850K? Too many registers to save/restore on interrupts? Reaper not optimized for 1800x?

fireberd
I recently (December) built an i7 6700K system.  It should last me for many years.  I don't feel "inadequate".  its a 6700K but I don't really plan on overclocking it, happened to get the 6700K model for the price of the 6700. 

Seriously, my i5-3350P wasn't choking on anything I do, so I figure the 6700 will carry me for a good long while.

Thanks Jim!