I think it was mentioned that some of the high CPU % was related to Spectre/Meltdown. I myself used to run 4 clients for mining (at around 20fps each, so not perfect, but would work), or 3 running easily in active combat sites, but ever since at some point (that coincided with the ‘enforcing’ of the 64bit release, if memory serves well) my machine barely can handle 2 clients. GPU usage % its surprisingly low, and also VRAM use… its very low.
But, recently, a client of mine that is using the same hardware I use (same mobo, same apu, different ram) gave me the computer to check, and decided to run memtest on both, and it was surprising to see that the CPU section of the test, showed that her computer’s numbers on L1 and L2 cache were double than mine, and that got me thinking that maybe that Spectre/Meltdown patch reduced my system performance (and didnt on hers because she’s using Windows XP so I guess that microcode patch is not available there? I can only guess).
But this could explain why I could run barely 4 clients before and now barely 2.
(Memtest also showed my ram was at fault, so untill new memory arrives (hopefully the coronavirus doesnt affect much mail delivery) I can’t run any more tests on my PC.