I'm also having some performance issues I don't seem to be able to get a grip on. I have the RX 480 (Asus Strix 8GB) working with Metal-support and all, but ut doesn't seem like it's fully enabled. Under 10.12.4 I got an OpenCL score of 138511 in Geekbench 4, but after upgrading to 10.12.5 I only get 94274. Tried Cinebench R15 and got 134.44 fps in the OpenCL test, which is in line with what n4ttcr4wl3r reports. I don't, however, have any pre-upgrade numbers to compare to in Cinebench.
I'm a bit of a noob when it comes to Hackintoshes, this being my first one, so this forum has helped me tremendously. When upgrading (I had forgotten to turn off automatic updates...), I followed the same steps I took for the 10.12.4 update as given in this thread (adding the 0x67df identifier in the 9510 and X4100 kexts and the "enable all CUs" patches in config.plist), but the results are not the same.
I'm at a loss, but, from reading the above, does anyone see what I've missed? Or have I not provided enough information?
E: Realised this was my first ever post on the forum after lurking for the better part of two years. So, Hello all!