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jayducharme

macrumors 601
Original poster
Jun 22, 2006
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I've had my 2018 mini for about five months (6-core with 32 gb RAM and 1 tb SSD). I also have the Razer Core with a Radeon RX 5700 (8 gb) card. The only connection to my LG 4k monitor is the mini, through an Apple-recommended TB3-to-DisplayPort cable. I do a lot of 3D graphics and Final Cut work. My 2013 Mac Pro had 4 gb of graphics power, and it seems lightning fast compared to what I'm getting out of the mini. 3D modeling that didn't skip a beat on the Mac Pro stutters badly on the mini. I figured double the graphics memory would help make up for the slight bandwidth loss of the TB3 cable. But even though I can hear the fans on the Razer speed up, any rendering gains are negligible. When I'm working in Final Cut, rendering takes forever (and yes, the Razer fans are revving during that process as well).

So I've been researching this for a while. Someone recommended connecting the eGPU simultaneously to the HDMI port on the monitor. I did that, and saw a very modest gain in 3D rendering capability. But that began complicating other things. Although 3D rendering was a little quicker, Final Cut was even slower! Games on Steam slowed to a crawl. If I used System Preferences to switch display inputs in the OS and then switched the monitor's input accordingly, I was able to play the games and Final Cut worked okay, but 3D rendering was back to a crawl.

The OS (the latest Catalina update) seems to have no problem recognizing and initiating the eGPU when needed. It's just that the eGPU doesn't seem to be helping much outside of blowing air around. The Razer enclosure is highly recommended, but did I get the wrong card? Is there some other way I'm supposed to connect this setup? I'm just not seeing as much benefit as I expected.
 

AnonMac50

macrumors 68000
Mar 24, 2010
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What if you directly connect the monitor to the eGPU using a DP cable? Would that be better?
 

jayducharme

macrumors 601
Original poster
Jun 22, 2006
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That was my first thought when I originally set up the system. But things actually ran slower that way, and I couldn't seem to get the frame rate above 30 fps. With the DP cable direct from the mini, the frame rate is a steady 60 fps.
 

jayducharme

macrumors 601
Original poster
Jun 22, 2006
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What if you directly connect the monitor to the eGPU using a DP cable? Would that be better?
I took the Razer Core apart. There weren't very clear instructions on connecting the cables to the graphics card, with two connectors left hanging. So I flipped the connectors around and tried going direct with the DP cable into the monitor. Everything is working great now, much speedier than it was before. So maybe I had the cables backwards. Thanks for your suggestion; it made me re-look at how everything was hooked up.
 

cheezeit

macrumors 6502
Jul 10, 2010
493
55
Dallas, TX
Can you elaborate or post photos on what was hooked backwards? I’m looking to get the same setup soon and don’t want to make the same mistake and be disappointed in the performance
 

jayducharme

macrumors 601
Original poster
Jun 22, 2006
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They're the power and data cables. The Razer Core X has two identical sets. One set will leave you with an extra power lead hanging off. There weren't clear instructions on which cables went where, so I had just guessed.
razer-cables.jpg
 

Brodlum

macrumors member
Jun 14, 2018
38
22
Are you running 10.15.4? macOS (clean install) doesn't work for me via eGPU since updating.
 

jayducharme

macrumors 601
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Jun 22, 2006
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I had a clean Catalina install when I got the mini, but since then I've simply updated as usual. So I have the current update, and everything seems to be working fine for me.
 
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Brodlum

macrumors member
Jun 14, 2018
38
22
Ahh, okay I have the XT variant and I'm facing huge issues on 10.15.4. I received mine on 10.15.3 and see no boot logo or startup manager (so can't boot to another drive), and now since 10.15.4 I get absolutely no video output via eGPU. Weirdly, when it's plugged in I can't even shutdown my Mac. :'(
 

jayducharme

macrumors 601
Original poster
Jun 22, 2006
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The thick of it
I had that problem when using HDMI with the Razer. For a while, I was using this cable directly out of the mini into my monitor, and I was using the Razer only for extra horsepower with a TB3 cable.


It worked really well, with full resolution at 60 fps. But I wasn't getting the full benefit of the eGPU. So now that I think I have the cables wired correctly, I'm going DP out from the Razer directly into the monitor. The mini is connected only to the Razer, and it boots fine now. I think the key in all this, as AnonMac50 pointed out, was that DisplayPort cable. It seems to work much better than an HDMI connection, and the OS seems to readily recognize it.
 
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Brodlum

macrumors member
Jun 14, 2018
38
22
Hmm, thanks for the tip! I've got three monitors, two over DP one over HDMI (all three via eGPU right now). Once the OS is booted on 10.15.1 it seems fine, I'm about to go test 10.15.3 again, but 10.15.4 just broke everything. (I've tested each of those three OSs three times now).

I have a fair few USB C to DP cables laying around, so I'll give them a go next. Not really willing to sink any more money into this until I get a response from Apple.

To confirm, do you get the boot logo to show up via eGPU? And if you hold down option at boot do you get the startup manager (drive selection)? AppleCare support has been fairly undertrained on this, not even knowing what an eGPU is :(
 

jayducharme

macrumors 601
Original poster
Jun 22, 2006
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The thick of it
To confirm, do you get the boot logo to show up via eGPU? And if you hold down option at boot do you get the startup manager (drive selection)? AppleCare support has been fairly undertrained on this, not even knowing what an eGPU is :(
Yes, I get the boot logo. (I even did the little trick through Terminal to re-enable the classic Apple start-up sound.) My mini now works as if it's connected directly to the monitor.

I guess it's the old case of YMMV, but an Apple tech I spoke with over the phone was the one who told me to originally try that USB-C-to-DP cable, which carried me through until I resumed doing 3D rendering and discovered that the eGPU wasn't pulling its considerable weight. Apple does recommend going directly out of the eGPU into a monitor, but it might be an issue of which graphics card you have. I took a chance because until recently, the Radeon 5700 wasn't supported. But I didn't want to invest a lot of money in 2 year old graphics cards (which were the ones Apple had initially recommended). I'm glad things are finally working for me. But I'm not driving three monitors, like you. I'm wondering if the HDMI connection might be causing the glitch.
 

Brodlum

macrumors member
Jun 14, 2018
38
22
Yes, I get the boot logo. (I even did the little trick through Terminal to re-enable the classic Apple start-up sound.) My mini now works as if it's connected directly to the monitor.
Hmm, that's super interesting then! I'm hoping they fix support for the 5700 XT soon then (though it's still not in 10.15.5b2 😢)

I pulled out all my other DPs & HDMIs and plugged in only one DP->USB C, but I ended up with no display, weirdly (yet unsurprisingly, at this point).

I held out for so long due to the 8th gen CPU and lack of discrete graphics too, but ended up having to bite the bullet as my MBP is crippling productivity. The 5700 XT & Razer Core X is even on their list of recommended configurations now; it's what led me down the Mac mini route in the first place. It's an absolute nightmare and I've wasted three days on it now. AC get back to me on Thursday (hopefully) with notes from an engineer. I'm expecting this not to be fixed for a good few months at least, sadly.

Stuck having to iterate through macOS updates to work out which one fails the least. 10.15.1 seems to slow down over time, to a point where everything but my cursor ends up freezing for 20 seconds every half a minute. Nightmare.
 

jayducharme

macrumors 601
Original poster
Jun 22, 2006
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It's an absolute nightmare and I've wasted three days on it now.
Sorry to hear that. If it's any consolation, it's taken me four MONTHS to figure out what was going on with my configuration, trying all sorts of different fixes. It sounds like you've got something more going on than just with your eGPU, though. My mini has generally behaved itself. It was just the graphic sluggishness that was causing me fits. I hope you get it worked out.
 
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