AMD Opengl seem to put a lot of strain on the CPU compared to its competitors GPU's I only used this GPU on one game/application zwift have tried multiple things but I'm still miles away from the performance of a GTX 1060 and along way behind a GTX1050.
I have tried the GPU with i5-3570 and 4x4gb DDR3 ram which was marginally better but but the system I use is a AMD phenom II 965 with 8gb DDR 3 I have tried 16gb but no difference. with a San disk extreme SSD this is a clean install with only zwift and the latest Adrenalin driver 19.4.1 i used the AMD clean up utility in safe mode to clean up any other drivers
Below are some screenshots from zwiftalizer
I don't have RX570 1440 ultra comparison as ultra profile is not unlocked on the 570 cannot select the ultra profile nor do I have a 1440 high as the minimum profile on the GTX 1060 is ultra.
Opengl driver of AMD is horrible !!! BUT DirectX 12 is Perfect :
(I get rank with my RX580 similar to GTX1080ti)
Your right there
Yes
I agree that the AMD OGL driver is not as good, and that is a shame as at one time I really believed it to be superior. That being said, having in the last 2 years gone from a Phenom II X6 with a HD 7950 to a RX 580 and it still being slow I figured it was time to get a new CPU and I did. Later on that PII X6 I had a 1050 and 1060 in that machine to test with. I can tell you for a fact those Green Team cards are also not as CPU dependent as your 570 is as them both performed a ton better. The 580 as a card should run circles around my 1050 Ti but vice versa is the reality on the PII. So you likely are also just more CPU limited between the cards you mentioned as well. Even that i5 would bottleneck the 570 more than the others. With an up to date CPU I think you would be a lot better. I however think you can still be okay with those older CPUs pairing them with the right GPU.
Think i need a CPU upgrade I've been studying CPU performance I was looking at Ryzen 2600 or 2700 although great CPU for multi tasking etc. I only want it for one use and it performs poor in Zwift See AMD CPU's
Verses Intel's
Intel's are between 30-50 FPS AVG more
and coupled with a AMD GPU the results are even worse. see the FPS approx 10 fps avg lower.