In terms of overall gaming performance, the AMD Ryzen R7 1800X is massively better than the AMD Ryzen R5 1600 when it comes to running the latest games. This also means it will be less likely to bottleneck more powerful GPUs, allowing them to achieve more of their gaming performance potential.

The Ryzen R5 1600 was released less than a year after the Ryzen R7 1800X, and so they are likely to have similar levels of support, and similarly optimized performance when running the latest games.

Both CPUs exhibit very powerful performance, so it probably isn't worth upgrading from one to the other, as both are capable of running even the most demanding games at the highest settings (assuming they are accompanied by equivalently powerful GPUs).

The Ryzen R7 1800X has 2 more cores than the Ryzen R5 1600. 8 cores is probably excessive if you mean to just run the latest games, as games are not yet able to harness this many cores. The cores in the Ryzen R5 1600 is more than enough for gaming purposes. However, if you intend on running a server with the Ryzen R7 1800X, it would seem to be a decent choice.

The Ryzen R7 1800X has 4 more threads than the Ryzen R5 1600. Both the Ryzen R7 1800X and the Ryzen R5 1600 use hyperthreading. The Ryzen R7 1800X has 2 logical threads per physical core and the Ryzen R5 1600 has 2.

Multiple threads are useful for improving the performance of multi-threaded applications. Additional cores and their accompanying thread will always be beneficial for multi-threaded applications. Hyperthreading will be beneficial for applications optimized for it, but it may slow others down. For games, the number of threads is largely irrelevant, as long as you have at least 2 cores (preferably 4), and hyperthreading can sometimes even hit performance.

More important for gaming than the number of cores and threads is the clock rate. Problematically, unless the two CPUs are from the same family, this can only serve as a general guide and nothing like an exact comparison, because the clock cycles per instruction (CPI) will vary so much.

The Ryzen R7 1800X and the Ryzen R5 1600 are from the same family of CPUs, and thus their clock speeds are directly comparable. With this in mind, it is safe to say that with a 0.4 GHz faster base clock rate, the Ryzen R7 1800X manages to provide slightly better performance than the Ryzen R5 1600. What is more, the Ryzen R7 1800X also manages to eke 0.4 GHz higher frequency when being stressed by CPU-intensive applications.

Aside from the clock rate, the next-most important CPU features for PC game performance are L2 and L3 cache size. Faster than RAM, the more cache available, the more data that can be stored for lightning-fast retrieval. L1 Cache is not usually an issue anymore for gaming, with most high-end CPUs eking out about the same L1 performance, and L2 is more important than L3 - but L3 is still important if you want to reach the highest levels of performance. Bear in mind that although it is better to have a larger cache, the larger it is, the higher the latency, so a balance has to be struck.

The Ryzen R7 1800X and the Ryzen R5 1600 have the same L2 cache size, and the same L3 cache size, so in terms of cache-related gaming performance, we have to look back to the clock rate, where the Ryzen R7 1800X wins out.

The maximum Thermal Design Power is the power in Watts that the CPU will consume in the worst case scenario. The lithography is the semiconductor manufacturing technology being used to create the CPU - the smaller this is, the more transistors that can be fit into the CPU, and the closer the connections. For both the lithography and the TDP, it is the lower the better, because a lower number means a lower amount of power is necessary to run the CPU, and consequently a lower amount of heat is produced.

The Ryzen R5 1600 has a 30 Watt lower Maximum TDP than the Ryzen R7 1800X (though they were created with the same size 14 nm manufacturing technology). What this means is the Ryzen R5 1600 will consume significantly less power and consequently produce less heat, enabling more prolonged computational tasks with fewer adverse effects. This will lower your yearly electricity bill significantly, as well as prevent you from having to invest in extra cooling mechanisms (unless you overclock).