MP 1,1-5,1 Mac Pro 5.1 vs MacBook Pro mid 2012 / hd7970 gpu issue?

[undox]

Hi there,

I can't get...

I own a
mac pro 5.1 2x 3.1 Ghz 6 core / 48 GB RAM / 1TB NVMe / hd7970 3GB runnig Mac Os Mojave 10.14.6
vs.
macbook pro 2x 2.4 Ghz dual core i7 / 16 GB RAM / 1TB SSD / 512 mb nividia geforce GT 650m running Mac Os Mojave

I have GPU issues when performing an audio program like Ableton live or comparable at the mac pro. The frame rate drops to 15fps and lower.
For Benchmark I run the same project, with the same program version, with the same monitor 4k at the same resolution (1440).
the mac pro gets 15-25 fps vs. MacBook Pro over 40fps staple.

-> we all know there are no Cuda driver's for Mojave and the Nvidia card
-> all benchmarks like unigine heaven seems ok for the hd7970 (test in mac os and win10)
-> the GPU performs solidly in win10, for programs like Ableton or Touchdesigner or games

Why is the performance so laggy in mac os? Why the much lower-powered card (Nvidia) performs so much better on the same OS?
Is it the Metal performance?

I go nuts, I search a while but I found no solution (disable the vertical Sync doesn't help).

Many Thanks in advance.

 

[undox]

update:
it seems that the hd7970 has a problem when the 4k monitor ist connected in DisplayPort 1.2 mode.
But with DisplayPort 1.1 I only reach a resolution of 1440 or via HDMI 4K (not able to scale only native resolutions).
I think it is a driver problem of mac os mojave with the AMD HD7970

no answer yet