Agner`s CPU blog

1.Currently win10 power management is not Zen aware, so either you park cores and get very slow wake up and get the XFR clocks or you disable core parking and don't get the XFR clocks. AMD released a work around power profile, but its a stop gap, Zen needs the equivalent of intel speedstep support in windows.

2. Memory latency is high, lots of initial reviews where done at DDR4 2133/2400 with high timings resulting in around 100ns memory access times in canned benchmarks (sandra, ADIA, sysmark etc). With new BIOS memory latency is lowered and higher frequencies are becoming easier to hit eg. 3200mhz CAS 14/16 . This is bring those memory latency numbers down to low 70's and on some motherbaord/memory combinations high 60's.

3. Inter CCX fabric clock and thus latency/throughput is tied to memory clock, so between this and point 2 upping memory clock has a big performance impact in gaming far bigger then on intel platforms. my guess is latency both inter CCX and to memory but i guess it could be throughput.

4. Nvidia Drivers seem to run into performance issues in many games above 4 physical cores. Its an odd problem, cant be clearly seen in all games, but as core counts increase NV performance can go backwards while Radeon performance goes forward. This can be seen on both Broadwell-E and Ryzen. Given the current GPU landscape this wasn't picked up initially because everyone tested on 1070/1080/1080ti etc and tested 1800X's against 7700k's.

5. Some games are doing things Zen doesn't like, AOTS got 20% perf up lift via a patch, we will have to wait and see what other games bring.

Unfortunately regular hardware sites aren't keeping up with this very fluid and changing environment, you have to take to forums and youtube reviewers (yuk) to see this stuff being tested.