Ati tool works for me but does not allow me to overclock as high when using amdgpu tool. So i then tried using atitool to crank fan speed full and amdgpu tool to overclock and got aroung 17600. So my last resort was to hard wire the 2900xt fan to power running at full speed and using amdgpu tool to overclock was my best result. I believe that the latency of the ram changes over 1000mhz prolly why performance drops. 975 chipset with ram running at 1100mhz still owns.
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