2014 27" iMac 5K (R9 M295X) [4th,4C,K] + RX 580 @ 16Gbps-TB2>TB3 (Sonnet Breakaway 350) + macOS 10.13.2 [secretsquirrel]
iMac (Retina 5K, 27-inch, Late 2014), 4 GHz Intel Core i7, 16 GB 1600 MHz DDR3, 1 TB Flash, AMD Radeon R9 M295X 4 GB graphics
Built-in Retina Display @ 2880 x 1620, DELL U2715H @ 2560 x 1440 - connected mDP->DP cable
macOS 10.13.2 (17C88)
Sonnet eGFX Breakaway Box 350
Sapphire Nitro+ Radeon RX 580
Apple Thunderbolt 3<->2 adapter, white Apple Thunderbolt cable 2m, DisplayPort -> Mini DisplayPort cable 1m
The installation process was quite simple, assembled the eGPU enclosure, attached the cables ->
- Attached the graphic card DisplayPort with an DisplayPort->Mini DisplayPort cable with my DELL U2715H monitor
- Connected the Apple Thunderbolt 3<->2 adapter and the white Apple Thunderbolt 2m cable
- Turned on external monitor
- Turned on iMac
- Connected the Tunderbolt cable with the iMac
- Received a prompt from macOS that an external GPU was detected and I should log out to begin using the external GPU
- Logged out and logged in again and the eGPU was working under macOS, the eGPU is recognized as AMD R9 xxx 8 GB
Here some benchmarks:
LuxMark v2.1 (sala scene):
- eGPU RX580: 3749
- iGPU R9 M295X: 1935
LuxMark v3.1 (luxball scene) - macOS: 15473
Unigine Heaven Benchmark 4.0 @ 2560x1440 8xAA fullscreen - Ultra - macOS:
- eGPU: FPS 25.6, Score 645, Min FPS 11.5, Max FPS 41.0
- iGPU: FPS 15.7, Score 395, Min FPS 8.2 Max FPS 27.2
Unigine Heaven Benchmark 4.0 @ 2560x1440 8xAA fullscreen - Ultra - Bootcamp Windows 10:
- eGPU: FPS 49.9, Score 1257, Min FPS 8.3, Max FPS 89.8
This eGPU build is my second attempt and works out of the box without any hassle, just plug'n play.
My first attempt with the HP Omen Accelerator didn't end so well.
The Omen was never recognized and it never turned on. I assume that my Omen was delivered with an older firmware, but due the lack of a native Windows PC with Thunderbolt 3 ports I couldn't verifiy this and I replaced the Omen with the Sonnet Breakaway Box, which is by the way much smaller than the Omen.
This eGPU setup with the same connections also works on a
Macbook Pro (Retina, 13-inch, Mid 2014), 2,6 GHz Intel Core i5, 8GB 16000 MHz DDR3 with Intel Iris iGPU on macOS 10.13.2 (17c88).
If you have any question or further remarks, please don't hesitate to ask...
Hey! great post. Im planning a similar build.
I wanted to ask: How is the system performing after the latest update from Apple (10.13.4 if you updated). In the release they state that egpu support for thunderbolt 2 has been dropped.
Hey, could you explain how you managed to make it work in windows? I’ve been trying for a while with Imac 5k late 2015 R9M390 and akitio node rx 580 and no luck! just crashing , black screen, half screen, error 12.....
I managed with MBP 2016 touch bar nicely though!
thank you very much! Not a single egpu implementation with Imacs out there!
i have the same imac.
is it possible to build that without an external Monitor?
I want to speed up the internal monitor.
lg from austria
Hello good day!
I have a similar iMac right now which I intend to make the most of by using an eGPU with the same setup like you have. My questions are the following:
1. Will you still be able to make it work with macOS Catalina 10.15.3
2. Do you really need an external display to make it work?
Thank you very much for any response.