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waterchill

macrumors member
Original poster
Aug 19, 2016
43
10
Hi there,

my situation:

Mac Mini 2018 i7/32GB/1TB + eGPU MSI Vega 64 + Sonnet 650

All three monitors 4k (LG 31MU97) hooked up to the Vega 64 Displayport

Just plugged in the eGPU restart and I'm disappointed.

First test:

Go to Google Chrome and check this link:


Play it at 8K resolution.

a) 8k video not possible to show this smooth (About 10fps). It is stuttering. GPU fans goes to full speed and GPU is maxed out. With internal graphics no problem.

b) Starting "zwift" some will know this for cycling indoor app. It is stuttering. GPU fans goes to full speed and GPU is maxed out. With internal graphics no problem.

c) Open "Microsoft Remote Desktop" It is stuttering. GPU fans goes to full speed and GPU is maxed out. With internal graphics no problem.

d) Start the screensaver, this is really disappointing. About 2fps on all three monitors and GPU fans at full speed.

What do I'm doing wrong? Is this normal?

With my old Mac Pro 6,1 D500 there was no problem with all these things, and the D500 is about 80% slower than the RX64 so what is the problem? I have no idea. Restarted the machine several times no improve. In Cinebench I get 110fps / 1217cb. System is fresh installed on 10.14.2
 
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I tried differend ways to connecr the displays, but in every possibility have the same result. 2 screens direct to mac and the third on the egpu or 2 on gpu one on mac and so on. I really cannot understand why the performance is so slow. The simple screensaver is much faster if hooked up all three displays directly instead connect sto egpu. This egpu is 5 times bigger than the whole macmini but has less performance?
 
I found out that only the 2 screensaver „Arabeske and shell“ maxes the eGPU out. All other screensavers are fine. This also not work with 1 screen you can test it. Bug?
 
I found out that only the 2 screensaver „Arabeske and shell“ maxes the eGPU out. All other screensavers are fine. This also not work with 1 screen you can test it. Bug?

With my monitor and external GPU (see signature), all of the screensavers, including Arabesque and Shell, work, although Shell doesn't seem terribly fluid. Do you even use the included screensavers, or is this an academic exercise?
 
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Only the included screensaver. This is a fresh installation for testing. If I choose arabesque or shell and click preview 10 seconds later gpu fans speeding up to max and it is about 5fps very very slow
 
I guess that I'm mostly interested in how my external GPU performs with applications like Final Cut, and with games, and just don't see the point of getting exercised over a couple of screensavers.

But then, I'm also not trying to use the mini and an external GPU to watch 8K content on three 4K screens at once. I can't even think of a reason why someone, including a professional filmmaker, would do that.

It would be great if you'd run some benchmarks on your Vega 64 and post them to the External GPU (eGPU) Resources thread, especially Cinebench, Unigine Valley and GFXBench Metal. The latest benchmark, for my Vega 56, is here: https://forums.macrumors.com/threads/external-gpu-egpu-resources.2154653/page-13#post-26913729 You'll find lots more, including some for the Vega 64, if you browse over the last few pages.

Looking forward to seeing your benchmarks.
 
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I don't know a ton about it, but from what I gather, I think that 4K/8K youtube videos in Chrome put the vast majority of load on the CPU because macOS doesn't have native GPU hardware support for VP9. Chrome therefore uses software decoding which puts the workload on the CPU.

My i5 Mini can handle a single 8K stream - activity monitor shows ~350%. 2 streams pegs the CPU at 600% (100%) utilization with stutter.
 
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This post makes me nervous. My mini is arriving Monday and I already have a Core X with a Vega 64 in it waiting... I don’t like reading these Mac mini “issues” posts.
 
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This post makes me nervous. My mini is arriving Monday and I already have a Core X with a Vega 64 in it waiting... I don’t like reading these Mac mini “issues” posts.
Consider using your mini before speculating bad performance. It's not a bad machine (though apple could have made these cheaper). It also doesn't change the fact that the i7 custom BTOs are one of the fastest apple has to offer outside of high end pro machines right now.
 
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Hi there,

my situation:

Mac Mini 2018 i7/32GB/1TB + eGPU MSI Vega 64 + Sonnet 650

All three monitors 4k (LG 31MU97) hooked up to the Vega 64 Displayport

Your problem is bandwidth; Thunderbolt 3 has not enough bandwidth for three 4K monitors. That's why the Blackmagic eGPU has only one HDMI connector, and even the new Blackmagic eGPU Pro has many fewer ports than an off-the-shelf 480/580/RX Vega.
 
Thank you for all your answers, sorry for my bad english. I will will start from the beginning and try to explain my problem and my daily usage.

For my normal daily usage I not really need 3 screens. I write invoices, surfing around show netflix and so on. My second job is trading, for this a have a second "real PC". This machine has no screens. What I'm doing is to go over Remote Desktop and control this PC. So far I did this with my MacPro 6,1 and the result was very good. This RDP Software has a lot of GPU usage not CPU. On the Mac it only uses 1 of the D500 cards which is in full load.

But I wanted something new, the mac is about 6 years old, so I thought why not buy a new mac mini + eGPU. This can be much faster, because new GPU and so on. But I was disappointed. And the I started to search. Is the only Problem the Remote Desktop? Or is there more. And the I found out this thing with the 8K video or this screensaver thing. The screensaver was a simply accident, I left my desktop for about 30min and the screensaver kicked in by default. I saw about 5fps on the screens and a heavy loud GPU.

The next thing is, my three screens has Displayport input and HDMI but only HDMI 1.4 which means that I can only hook up 4k@30hz which i really bad. Solution: Buy new Monitors or buy eGPU. I started with eGPU. I think I will send back the GPU and the case and go for RX590 in a smaller case. Best solution so far is hook up 2 screens directly to the mac and the third to the eGPU. This is also not a good performance (about 50% less than my mac Pro) Or sell also the MacMini and wait for the new mac pro.

The Mac Mini is a nice thing, but for my porposes not the right one.

I did all this benchmarks you told. The GFX Open GL Test is not possible to make, it says it is not supported.
 

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Hi,

For GFXBench, the right app is GFX Metal, not GFX OpenGL. As you say, the latter no longer works, presumably because Mac has moved from OpenGL to Metal. But thanks, the benchmarks that you did are really helpful.
 
Here is the GFXBench Metal Test for your reference.
 

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I guess when my machine arrives I will let the screensaver kick on and see what happens with my Vega 64 and Core X box. This does have me a little concerned, but maybe all for nothing. I will be running two BENQ 2560x1440 screens via DP going directly into the eGPU box. Hope this is smooth...
 
For this resolution it should go without any problems I think, we will see.

After testing yesterday around, finally I fired up my MacPro trashcan, restored my backup and all thing are fine now. I will send the MacMini back include eGPU and so. Hopefully there will be a new MacPro this year.
 
For this resolution it should go without any problems I think, we will see.

After testing yesterday around, finally I fired up my MacPro trashcan, restored my backup and all thing are fine now. I will send the MacMini back include eGPU and so. Hopefully there will be a new MacPro this year.

I only use 1 screen and experience no problems, but I'll keep in mind that using 3 screens, there might be a bandwidth issue. I wonder if you would have had issues if you only connected 2 monitors on the egpu and 1 with the built in 630.
 
The issue with the screensaver and the 8K video exists also on 1 screen. You can check your GPU usage playing a 4K video. With UHD 630 load is about 20%. With eGPU load is about 80%. And please do not forget one thing. The MacPro has one fan. If using a eGPU this thing has 3 or 4 fans + the fan mac mini. It is very noisy if all fans are on full load. I think if you are using 2 screens or more, better to get an used MacPro. You can also connect an eGPU if needed.
 
I can confirm what the OP is saying is true. Even when only using two 2560x1440 monitors. Things really lag with the Arabesque screensaver and the fans spin up full speed. Totally annoying. Wonder what the issue is? I am plugged into a Core X eGPU running a Vega 64 card.
 
I can confirm what the OP is saying is true. Even when only using two 2560x1440 monitors. Things really lag with the Arabesque screensaver and the fans spin up full speed. Totally annoying. Wonder what the issue is? I am plugged into a Core X eGPU running a Vega 64 card.

Could you explain why anybody would care? I mean, I've tried this myself, Arabesque was fine, Shell was slow, but they're screensavers. When evaluating my external GPU, they aren't even on the list of things that I care about.

And now you've posted about this in not one, but two threads, the second of which is about the LG 5K monitor that the poster here isn't even talking about, and that you don't have yourself?
 
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Could you explain why anybody would care? I mean, I've tried this myself, Arabesque was fine, Shell was slow, but they're screensavers. When evaluating my external GPU, they aren't even on the list of things that I care about.

And now you've posted about this in not one, but two threads, the second of which is about the LG 5K monitor that the poster here isn't even talking about?
Yeah it is Shell that lags badly in screensavers and ramps the fans to full speed. Arabesque is ok. Personally I don't really care what you do or do not care about. If you don't care, don't comment. Neither the OP or myself need to explain anything to you. We are merely documenting our experience with these new machines. Have a nice one.
 
Yeah it is Shell that lags badly in screensavers and ramps the fans to full speed. Arabesque is ok. Personally I don't really care what you do or do not care about. If you don't care, don't comment. Neither the OP or myself need to explain anything to you. We are merely documenting our experience with these new machines. Have a nice one.

Sorry, but the point of my post was to ask you why anyone using an external GPU would care. Apparently your response is that you are "merely documenting your experience". Cool, although I wonder what the point is of "documenting your experience" in two different threads, one of which is about a monitor that neither you nor the original poster here are even using, let alone about using two or three monitors at once.

Also, while I now understand that you are just "documenting your experience", I might be forgiven for assuming that you meant your question - what is the issue? - to be taken seriously.
 
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I also get this weird red square that flashes for a second on startup. Happens every time, whether doing a full power on or a restart. It occurs right before the login screen.
 
Sorry @1071318 to hear about that. I hoped that you didn't have this issues under this resolution.

@F-Train It is not only an issue with the screensaver. It is with many other daily things like zwift, Remote Desktop and so on. I believe when you install a RX64 in a normal PC or even an old cheesegrater mac pro, you will not run into these things. If an old d500 in mac pro can handle all things things easily why not a RX64? This card is 4 times faster and 5 years younger...

There is an other issue that I spotted out. First I thought this is maybe a setting thing or something but nope. Let me try to explain this.

Go to a browser, doesn't matter which one, open google and search for something. Than click the "search" button and you get a full page of results. A normal daily thing. Now if you go with your mouse over the results, your mouse arrow will change to a "hand" for click a link and if go over a text it changes to an other symbol, you know what I mean I don't know the word fo this, you can mark a text with this. So if hooked up one screen and you are connected direct to eGPU, go with your mouse all over the results you will see that the mouse pointer will slow a little bit down. Connect 2 screens, it slows much more down, with three screens, you need about double of the way with your mouse on your desk like normally. The window must be active. If leave the browser open and click to "finder" you go with your mouse normally over, because the arrow doesn't changes to the other things. This issue happens, because GPU is too slow or there is a software problem I don't know but I would like to understand, why there are issues like that.

To compare a MacMini and a MacPro is for me like MacMini is an 1 litre car with 2 turbos and with eGPU a charger on top and a MacPro is a V8 Big Block. With a V8 you will have generally less issues like a car with many gadgets on it.
 
I wonder if it has something to do with Vega64 drivers... Do you think you can try with a different GPU?
 
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