Performance On Final To MIA With New Mac Mini 2018 Disappointing

Question

I just upgraded from a 2012 Mac Mini to a 2018 Mac Mini with a Radeon RX 580 8GB eGPU in expectation that I could solve my non-real-time finals into KMIA (and other dense scenery airports).  While the new setup seems to do fine in the air, in weather, and at my home base airport KLNA (25-45 fps), the final into MIA still drops very low.

(Settings attached - The CPU shows 75-105% usage (up to 850% when loading).   Varying the graphics settings does not seem to be able to fix the issue.  If I set World Objects to Minimal the frame rate stays up just fine but there are no buildings what so ever - I really thought a six-core 3.2GHz processor with 2666 MHz memory could at least allow Objects:Low flying.  These tests were with 8GB main memory, X-plane is showing 5GB used with total memory used sitting at 5.5-6.8 GB.  I have 32GB on order, but these tests make be think memory is not the bottleneck in this case.)

I get enough "Maybe you should have bought a Windows machine for flying" from my wife, please don't tell me it is the fault of the operating system that X-Plane can't show me a few buildings at MIA.

Here is the graph for final:

 And my  settings:

Here is at my base Airport - very nice performance:

If I set Objects:Minimal the frame rate stays high for the whole flight:

But then the world is very flat:

BTW, the fps tests 1, 2, 3 results (with eGPU preferred set) are :

MacMini2018 8G Mohave 10.14.1 RX580 LG prefer external fps_test=1:
FRAMERATE TEST: time=92.8, frames=4093, fps=44.13
GPU LOAD: time=92.8, wait=5.7, load=6.2%

2018 MacMini 8GB, Mohave RX580 LG, prefer external fps_test=2
FRAMERATE TEST: time=94.2, frames=2506, fps=26.61
GPU LOAD: time=94.2, wait=2.7, load=2.8%

MacMini2018 8GB Mohave 10.14.1 LG RX580 prefer external fps_test=3:
FRAMERATE TEST: time=103.6, frames=2029, fps=19.59
GPU LOAD: time=103.6, wait=5.2, load=5.0%

Comments

As an experiment, I built a personal KMIA scenery pack with no cars, trucks, luggage carts, no luggage piles, no mobile jetways, no ATC, no ground routes, no parking spaces, no barriers, no trees, and all the roof detail deleted from the buildings.  

With all the deletions the frame rate hovered around 19-20.

I gave up on that idea, and installed the plugin Fly_with_LUA and script FPS-Wizard11 (target min 23).  This keeps the frame rate above the 19.9 minimum for real-time flight.  Additionally, it seems like I can fly 1920x1080 "full screen" with this plug-in managing the frame rate.

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Update January 2019:

I started out excited to have a new MacMini with a good size SSD, external GPU and 4k monitor capable of editing and viewing 4k video and my bird photos at 8MegaPixels.  My wife: "I thought you were going to have better flying graphics than **that**"

In the end I have had to accept that I flew my "personal x-plane LongEz" 100 hours in 2018. 

I used the computer for photo and video editing roughly 300 hours.  

I used the computer over 1000 hours for checking mail, reading news, reading and posting in forums, and about 100 hours for remote development of my robot.

Or In other words, I live on my computer.  (With iPad Mini, iPhone X, and this month Apple Watch 4.)

I prefer the Apple eco system for a whole lot of reasons, **and** I only want one computer and two monitors.  If X-Plane were more or most important, I would either need to have two computers, or one Windows computer.  (Or maybe investigate boot camp.) 

My 3.2GHz i7 2018 Mac Mini with 32GB memory, and the RX580 eGPU is CPU limited, so I can only run with "Number of World Objects: Low", 85 degrees FOV, 2179x1136 (19.5 inches wide x 9.5" high at 111dpi), which gives me 35-40 fps cruising in good weather and roughly 30 overcast at 140Kt in my "fast homebuilt GA airplane" (VSkyLabs LongEZ), and 30 on final to the non-major airports I fly most of the time.  These figures are with the 3jFPS-wizard11 plug-in which yields a 3 fps improvement in weather and a 10-15 fps improvement if I fly into a major airport.  (Major airports, e.g. MIA, are totally impossible without this plug-in.)  (One other setting: right click on the X-Plane.app->Get Info, and check mark Prefer External GPU)

This gives me great flying, with acceptable scenery.  I have been unable to get my TeamSquawk app to work on the 2018 Mini, so I cannot fly with IVAO or VATSIM ATC.  I'm thinking it is because there is no longer a mic in on the box.

 I am about to install Ortho4XP to see if I can achieve a more realistic world for VFR flying.