The 8 cores will give you more headroom (more plugins)vs the 6 cores but wont make things go actually faster (mixing down audio), you still can only go as fast as each core is limited to, thats why checking single threaded score is still relevant but probably the most important in judging a cpu, and in that case the 5600x and 5800x are about even in single threaded score, so no performance advantage in everday use but more headroom to do things, and why you should consider the 11700 which is the same as the 5800x but cheaper.. Personally id go intel just because ive read too many issues that involved AMD and stability which i dont want to deal with but im sure isnt the norm,. Ithink AMD handles memory differently so I would be curiouse to see how plugin latency which in part relys on memory speed to lower buffers performs on AMD. But without testing we'll never know and why with intel you know nothing funky is going to happen and with the prices become a better choice imo. With that said your 3core cpu is most likely light years behind in single threaded perfromancethat any upgrade in the cpu to a modern one would be a nice upgrade. The x5600 being a good choice because its up there on the single threaded side, x3700 being a worse choice since its low on the scale, a 11700 being a better overall choice i believe.