AMD Ryzen 2700x vs Intel i7-9700k
If you are in the market for a CPU in the $350 price range, you have two choices: Intel's i7-9700k or AMD's Ryzen 7 2700x. They both sport 8 cores and are within $80 of each other. In terms of specs, they both have their strengths and weaknesses. Intel employs 14nm manufacturing while AMD employs the newer 12nm manufacturing which should lower power consumption but AMD opts for more cache.
Features
In terms of specifications, besides the 8 cores, Intel and AMD are different animals altogether. AMD uses Simultaneous Multithreading which is essentially hyper threading and gives AMD the edge with 16 threads. Intel forgoes hyper threading for faster clock speed and provides "only" 8 threads. Intel comes in with 2MB of L2 cache and 12MB of L3 cache. AMD ups the ante by providing 4MB of L2 cache and 16MB of L3 cache. The Ryzen 2700X supports up to DDR4-2933 memory while the Intel supports up to DDR4-2666 memory. Intel is based on the older 14nm manufacturing process while AMD employs 12nm manufacturing process allowing AMD to pack more circuitry into a same space.
Performance
On the overall PassMark benchmark tests, the 9700K comes out slightly ahead is a score of 17,142 as opposed to 16,974. When it comes to single thread PassMark benchmark tests, the 9700K comes out ahead a score of 2.832 compared to the 2700X's 2.194. When it comes to games, the 9700k edges ahead of the 2700X for almost every game. In Grand Theft Auto V, the 9700k comes in with 108fps while the 2700X gets 90fps. In other gaming benchmarks, the difference isn't so pronounced such as Shadow of the Tomb Raider, the 2700X gets 75fps while the 9700K gets 76fps. Neither of these CPU's are slouches and most likely faster than what your current monitor can do. In terms of productivity, who comes out ahead depends on whether the application takes advantage of multithreading or not. If the applications uses multithreading like Cinebench 15, the 2700X has better benchmark scores. If the application only works in a single thread, the 9700K has the better benchmark scores.
Value
In terms of value, we are also splitting hairs. The AMD 2700K is about $80 less than the 9700K. The Intel 9700K has a built in GPU so a video card isn't necessary unlike AMD's 2700K. The 9700K has a slight edge when it comes to overall performance compared to the 2700X. The 2700K comes with a good CPU cooling fan where as the fan included in the 9700K leaves us wanting. In terms of PassMark's CPU value scores, AMD gets 55.66 as opposed to 43.37.
The slight difference in the overall performance of the Intel i7-9700K may not justify the price difference compared to the AMD Ryzen 2700K. That difference may be eaten by the extra cost of a GPU that the 2700K needs but most systems using this class of CPUs usually have separate video cards anyway. In the end, it may come down to which marketing propaganda makes you feel better.