Connect two LG 27UL850-W 4K displays to MacBook Pro (Retina, 13-inch, Early 2015...
 
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Connect two LG 27UL850-W 4K displays to MacBook Pro (Retina, 13-inch, Early 2015)  

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nkaretnikov
(@nkaretnikov)
New Member
Joined: 8 months ago
 

TL;DR:

I'd like to connect two LG 27UL850-W 4K displays to MacBook Pro (Retina, 13-inch,
Early 2015) with the following settings (using an eGPU):

Resolution: 5120x2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60 Hz

Summary:

I'm currently on macOS Mojave (10.14.6). Still not sure if I ever want to
upgrade to Catalina. I might just switch to Linux or Windows (could be on this
or a different laptop), so painless eGPU support across these three platforms is
desirable.

Here are the specs of my laptop:

MacBook Pro (Retina, 13-inch, Early 2015)
Processor: 2,9 GHz Intel Core i5
Memory: 8 GB 1867 MHz DDR3
Graphics: Intel Iris Graphics 6100 1536 MB

Each of the two LG 27UL850-W displays is currently connected with a 4K mini
DisplayPort/Thunderbolt to HDMI adapter and an LG-provided HDMI cable.

https://www.lg.com/us/monitors/lg-27UL850-W-4k-uhd-led-monitor
https://www.belkin.com/us/p/P-F2CD079/

With this setup, System Report lists:

Resolution: 3840 x 2160 (2160p 4K UHD - Ultra High Definition)
UI Looks like: 1920 x 1080 @ 30 Hz

This is okay, the fonts look fine, but there's not much space -- everything is
too big.

Clicking on Scaled (while holding Option) in System Preferences -> Displays:

3840 x 2160 (low resolution)
2560 x 1440 (low resolution)
1920 x 1080
1600 x 900 (low resolution)
1344 x 1008 (low resolution)

And so on. For instance, 3840 x 2160 is low resolution indeed. All UI elements
are too small and the fonts look terrible.

If I connect one of the displays to a Mac mini (2018) (running Catalina)
directly over USB-C, I get this (using one of the Scaled modes):

Resolution: 5120x2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60 Hz

(Connection Type is reported as DisplayPort.)

This is the configuration I'd like to get on the rMBP (with two external
displays): there's plenty of space and the fonts look good.

My current setup on the rMBP is the best I can get according to:

https://support.apple.com/kb/sp715

"Simultaneously supports full native resolution on the built-in display and up to
3840 by 2160 pixels on up to two external displays, both at millions of colors."

So I'm thinking of using an eGPU to get the same result as on the mini (but with
two external displays).

According to the manual, each display should support DisplayPort 1.4. (Not sure
about the HDMI version.) And Wikipedia says that 5K (5120 x 2880) @ 60 Hz is
supported since DisplayPort 1.3:

https://en.wikipedia.org/wiki/DisplayPort#1.3

As I understand it, connecting to an eGPU over Thunderbolt 2 is not officially
supported by macOS, and I want my eGPU setup to be future-proof anyway, so I'm
only considering Thunderbolt 3 enclosures. I also want to go with AMD since the
displays support FreeSync:

https://en.wikipedia.org/wiki/FreeSync

IIUC, (some) AMD GPUs are also supported by macOS out of the box.

Based on https://egpu.io/best-egpu-buyers-guide/#tb3-enclosures:

The only Thunderbolt 3 enclosure with 2xDP and 2xHDMI:

* Powercolor/ VisionTek mini with RX560 ($350) or RX570 ($480); has AC-ext.

Other Thunderbolt 3 enclosures with >=2xDP:

* AORUS/Gigabyte Gaming Box with RX580 ($420); has fATX-int.

* Sonnet Breakaway 350|550|650 without a GPU ($199, $280, $399) or
with RX580 ($439), Vega56 ($799), Vega64 ($949).

* Sonnet Breakaway Puck with RX560 ($399) or RX570 ($499); has AC-ext.

I don't want noisy fans nor am really interested in messing with external PSUs,
so I'm thinking of going with Sonnet Breakaway.

It also doesn't have any red notes (besides the max power one), which is a good
sign. (But this may depend on whether I find it in stock locally.)

As for the GPU itself, these are supported:

RX480/580 and everything listed here:

https://egpu.io/external-gpu-macos-10-13-4-update/#HS-AMD-support

Looking at the MSI website, only these show up with >=x2 DP 1.4
(x3 DP 1.4 + HDMI 2.0b):

https://www.msi.com/Graphics-card/Radeon-RX-480-4G/Specification
https://www.msi.com/Graphics-Cards#?tag=Radeon%E2%84%A2-RX-5700-XT

But RX 480 is hard to find (not sure if it's a good idea to buy a used card),
so which of the RX 5700 XT cards should I get?

Someone reported a performance issue with this card:

https://egpu.io/forums/builds/2013-13-macbook-pro-4th2cu-rx-5700-xt-16gbps-tb2tb3-razer-core-x-macos-10-15-1-vonthing/

But the OP never followed up when asked to run more benchmarks, so this can be
ignored, I guess.

Also, based on that post, is Sapphire Pulse really better than MSI? What about
Gigabyte cards? And I've read somewhere on the forum that XFX is not
recommended (the reddit link below seconds this). What about noise levels of
these cards? What's a reliable source of information on this?

According to this random post, the silent one is MSI RX5700XT Gaming X:

https://forum-en.msi.com/index.php?topic=324912.0

This guide, however, suggests to avoid Sapphire Pulse too:

https://www.reddit.com/r/hackintosh/comments/b91vf5/mojave_gpu_buyers_guide/

And it seems RX 5700 XT is only supported since Catalina:

https://khronokernel-3.gitbook.io/catalina-gpu-buyers-guide/modern-gpus/amd-gpu

Both RX 480 and RX 5700 XT should be compatible with Breakaway 550:

http://www.sonnettech.com/support/downloads/manuals/Compatibility_Graphics_Cards.pdf

Does the enclosure work with DisplayPort 1.4?

Will this setup be compatible with the current and future MBPs? E.g., the
current 16" one and the rumored 14" one?

It seems so, if I'm reading this correctly:

http://www.sonnettech.com/support/downloads/manuals/macos_egpu_info.pdf

Extra points:

* Is there a setup that would allow me to avoid messing with UEFI and/or
disabling SIP (e.g., by just adding a config file somewhere)? If disabling SIP is
required, will it be possible to re-enable it after applying the patches?

* As I said, this is not the current priority, but it would be nice to get
something that works fine with Windows and Linux.

* I also want something future-proof, which will work with a Thunderbolt 3/USB-C
laptop.

* Also, despite what I wrote about not wanting to mess with the external PSU,
I'm thinking maybe I should avoid using an enclosure, so that I can reuse more
parts for a different desktop build later. Is there a way to do what I want
by using an external PSU, some PCIe card, and a bunch of cables? What would
you recommend?

This topic was modified 8 months ago

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

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joevt
(@joevt)
Noble Member
Joined: 3 years ago
 

The LG 27UL850-W displays are 4K so you don't need DisplayPort 1.4 or 1.3.

The MacBook Pro (Retina, 13-inch, Early 2015) can support two 4K external displays, so you don't need an eGPU.

DisplayPort 1.2 supports 4K60Hz 10 bpc. HDMI has less bandwidth and therefore can do 8 bpc 4:4:4 or 10 bpc 4:2:2. Therefore, you should connect each display with a DisplayPort cable.

HDR requires an eGPU with DisplayPort 1.4. Connect the displays to the GPU in the enclosure.

If you don't see a 2560x1440 HiDPI mode, then you can try using SwitchResX to create a scaled 5120x2880 resolution. If the graphics drivers accept the scaled resolution after a restart, then you should see a 2560x1440 HiDPI mode in the Current Resolutions list in SwitchResX.

Use the DisplayPort connection of the monitor. Use the USB-C to USB-A cable to use the monitor as a USB 3.0 hub (USB-C to USB-C only allows USB 2.0 hub functionality).

 

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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nkaretnikov
(@nkaretnikov)
New Member
Joined: 8 months ago
 

@joevt, that Apple page is confusing. Indeed, my laptop is now running both
displays with the following settings:

LG HDR 4K:
Resolution: 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440 @ 60 Hz
Framebuffer Depth: 24-Bit Color (ARGB8888)
Main Display: Yes
Mirror: Off
Online: Yes
Rotation: Supported
Automatically Adjust Brightness: No
Connection Type: DisplayPort

Small fonts are a bit blurry with this resolution (e.g., Consolas 14 pt). I've
tried playing around with various anti-aliasing settings, but I guess nothing
can be done other than waiting for non-Ultrafine 5K 27-inch displays. I also
feel that the original resolution is easier on the eyes, but maybe it's just
because everything is so small with the scaled one.

Also, as a heads-up to people reading this: make sure to buy a quality Mini
DisplayPort to DisplayPort cable. While trying to find the right pair, I bought
a pair that couldn't work properly even after switching displays to DisplayPort
1.1: the image was a bit distorted and constantly "shaking." And do not buy an
adapter if you need to connect two displays, the ones I've seen are too wide to
plug in simultaneously. I wonder why there's no official or at least
Apple-endorsed third-party adapter or cable (which is the reason I initially
went with HDMI).

I guess I'll try running without an eGPU for now. But I'm still curious about
eGPU-related stuff from my original post. Sometimes the system feels a bit slow
(e.g., when scrolling things or using Mission Control, the cursor freezes for a
second from time to time too, which is annoying).

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

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joevt
(@joevt)
Noble Member
Joined: 3 years ago
 

@nkaretnikov

The info you see there does not show the resolution of the display. It only shows the resolution of the frame buffer.

Posted by: @nkaretnikov

And do not buy an adapter if you need to connect two displays, the ones I've seen are too wide to plug in simultaneously.

I don't understand what you mean. Can you post a link to an example adapter that has that problem?

DisplayPort 1.1 is not enough for 4K.

I only buy VESA DisplayPort 1.4 certified cables now. For DisplayPort to DisplayPort or Mini DisplayPort : club3d cables. For USB-C to DisplayPort, the moshi cable. For USB-C to Mini DisplayPort: Cable Matters USB-C to DisplayPort 1.4 adapter + club3d DisplayPort to Mini DisplayPort cable.

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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nkaretnikov
(@nkaretnikov)
New Member
Joined: 8 months ago
 
Posted by: @joevt

I don't understand what you mean. Can you post a link to an example adapter that has that problem?

I cannot post a link to the adapter because it has been removed from the
website. The issue is that it's a rigid piece of plastic which is as wide as
a DisplayPort connector. So you cannot use two of them at the same time since
the Thunderbolt ports on the rMBP are too close.

This is not the one I have, but it looks similar:
http://www.l-com.com/audio-video-displayport-female-to-mini-displayport-male-adapter

Posted by: @joevt

DisplayPort 1.1 is not enough for 4K.

Yes, I'm aware. I simply used it for testing because I couldn't get anything
with DisplayPort 1.4 and that faulty cable.

 

Any thoughts on eGPU stuff from my original post?

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

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joevt
(@joevt)
Noble Member
Joined: 3 years ago
 
Posted by: @nkaretnikov

Also, despite what I wrote about not wanting to mess with the external PSU,
I'm thinking maybe I should avoid using an enclosure, so that I can reuse more
parts for a different desktop build later. Is there a way to do what I want
by using an external PSU, some PCIe card, and a bunch of cables? What would
you recommend?

The only parts you can reuse are the PSU and GPU. You still need the parts to connect the GPU via Thunderbolt. Something that converts Thunderbolt to PCIe. A Thunderbolt 3 PCIe enclosure, or a Thunderbolt to M.2 NVMe drive enclosure.
https://www.sonnettech.com/product/echo-express-sel-tb3/overview.html
https://egpu.io/forums/which-gear-should-i-buy/thunderbolt-3-external-drive-slot-m-2-ngff-adapter/
https://egpu.io/forums/thunderbolt-enclosures/adt-link-r43sg-tb3/
https://egpu.io/forums/builds/2019-16-macbook-pro-rp5500m-9th8ch-rx-5700-32gbps-tb3-adt-link-r43sg-m-2-tb3-macos-10-15-1-win10-1903-itsage/

Posted by: @nkaretnikov

Is there a setup that would allow me to avoid messing with UEFI and/or
disabling SIP (e.g., by just adding a config file somewhere)? If disabling SIP is
required, will it be possible to re-enable it after applying the patches?

You have a Thunderbolt 2 Mac so disabling SIP might be necessary. I don't worry about SIP. Macs have survived before SIP was invented. Just don't click on weird stuff in web browser (e.g. if a web page says you have a virus, ignore it).

Posted by: @nkaretnikov

Will this setup be compatible with the current and future MBPs? E.g., the
current 16" one and the rumored 14" one?

Probably. You just need a Thunderbolt port to use an eGPU.

Posted by: @nkaretnikov

Does the enclosure work with DisplayPort 1.4?

The enclosure does not affect DisplayPort 1.4 compatibility. Only the GPU and drivers. All modern graphics cards support DisplayPort 1.4 (RX580, GTX1070, etc.)

Posted by: @nkaretnikov

And it seems RX 5700 XT is only supported since Catalina

True. Since 10.15.1.

Posted by: @nkaretnikov

Also, based on that post, is Sapphire Pulse really better than MSI? What about
Gigabyte cards? And I've read somewhere on the forum that XFX is not
recommended (the reddit link below seconds this). What about noise levels of
these cards? What's a reliable source of information on this?

They're all the same except where they are different. Find reviews that compare them. Then choose one that has good price/performance.
Check Gamers Nexus reviews. They seem thorough.
https://www.gamersnexus.net/guides/3536-worst-and-best-gaming-gpus-of-2019

Posted by: @nkaretnikov

But RX 480 is hard to find (not sure if it's a good idea to buy a used card),
so which of the RX 5700 XT cards should I get?

Get a RX 5700XT that others have tried. Or get one that others haven't tried. Don't get one that others have tried and failed.

 

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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