2017 27" iMac 5K (RP580) [7th,4C] + RTX 2060 Super @ 32Gbps-TB3 (Razer Core X Ch...
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2017 27" iMac 5K (RP580) [7th,4C] + RTX 2060 Super @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 1909 // Vive Cosmos Elite & Half Life Alyx  


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Joined: 2 years ago

Hi, I am Mooi.

At first, sorry for your inconvenience because I have a limited vocabulary . (I am from Japan, many Japanese are not good at English :P,  I wrote this using dictionary)

I am 38 years old and about 30-year Macintosh user (from Macintosh II or Color Classic II to present, about 10 machines) and  a FPS games lover since 7 years old(Bungie’s Pathways into Darkness, Marathon etc only on Macs), so buying a windows gaming machine means losing my principles for me.

I knew this site about several years ago. I was deeply moved for your hardships making eGPUs to work. My dream is making my Macs handling heavy FPS games and now dreams came true. 

My highlight is the Vive Cosmos Elite on Mac, playing Half life Alyx. At first, I searched in reddit or amazon reviews but (of course) no reports about the Cosmos elite on Macs. I suppose this is a big deal because everything costs 3000 dollars, but finally successful, I felt relieved.


System Specs

[System]: Apple iMac (Retina 5k, 27-inch, 2017)

[0S]: Windows 10 Build 1909

[CPU]: Intel core i7-6920 @ 2.90GHz

[dGPU]: AMD Radeon Pro580, 4GB DDR5

[RAM]: 16GB DDR4

[GPU Drivers]: for RP580, v20.4.1 (from bootcampdrivers)


eGPU Hardware

[enclosure]: Razer Core X Chroma

[eGPU]: MSI GeForce RTX 2060 super



MacsfanControl to reduce  the heat from CPU, I set min66 max86 degree for CPU#4 in the setting. Monitoring showed a spot 100 degree and constantly around 85 degree.


Installation Steps*(the alphabet means notes)

  1. Install Windows 10 home x64, on the external SSD drive without Bootcamp software(external drive is the optional, not always required) *a
  2. Run windows update normally, I don’t disable the auto update function because NVIDIA users do not report problems as I searched in this forum.
  3. install MacsFanControl
  4. Install the latest drivers using bootcampdrivers.com for dGPU.
  5. The above is what I always do before using windows on mac, nothing special for eGPU.

After all, I followed this procedure. Thanks a lot for reporters. I use [] for emphasis.

  1. boot windows
  2. Prepare eGPU attached Tb3 cable, power, switched off.
    connect external display to eGPU
    [Tb3 cable on iMac side not connected, eGPU swiched off]
    [iMac accepts only one direction for Tb3 cable, be careful and try]
    In this step, I also prepare for Vive. Cosmos elite has the USB typeA and the displayport. Attach this displayport to the eGPU side and [don’t plug the USB port to the iMac this time]
  3. plug Tb3 cable to the iMac side port, turn on the eGPU
    EGPU switched [ON]. If you need, the cable mouse and keyboard should be connected to USB ports on the eGPU. Turn on iMac, and immediately after Windows logo blinks, plug Tb3 cable in the iMac side
  4. Windows recognizes the eGPU, automatically install the required drivers, external display shows.
    updated: I forget to write make setting for “only shows the second display” in the screen settings*d
  5. no automatic pop up messages from Razer, so I manually download and install the Razer synapse software. 
    eGPU preparation is over
  6. next, attach the Vive USB port to [the iMac side]*b. Vive automatically starts
  7. After playing, shut down windows and unplug iMac side tb3 cable and Vive USB cable. When I play next time, repeat from Step#6.*c


a. This is bacause of iMac’s fusion drive. Bootcamp windows do not use the SSD part and partitioning in the bootcamp assistant sotware causes many errors, so I avoid it. I referred this site. the SSD drive is attached to the USB typeA port, using typeC port caused type12 error when connected eGPU.

b. When connect the Vive usb to the eGPU port, it is not correctly recognized, error message or BSOD occurred.

c. eGPU power switching on before Windows boot causes type 12 error or never recognize eGPU(in device manager, display adaptor shows nothing)

d. After the initial setting, I removed the external monitor. After that I can use the internal display and Vive without the external monitor. 


At first I tried using only dGPU RP580, which showed “VR ready” in steam VR performance test. But Vive connectors need displayport and iMac doesn’t have one. I use Cable Matters’s USB type C to Displayport cable. Vive worked, but refresh rate is unstable and noisy screen and  finally Vive suddenly stops recognizing headset. I wonder which caused error, RP580 or the cable.



Why does Tb3 cable have such a polarity?


May 26, 2020

  • I changed the direction of Tb3 cable some times, but all worked smoothly. So I delete mentioning the polarity of the cable.
  • Using the USB ports on eGPU made Vive unstable, causing BSOD thing or “display adaptor” errors. So using the port on the iMac side is needed.
  • Plug and play after windows boot made my magic mouse2 impossible to scroll. Plugging eGPU while windows logo avoid that loss of function. I don’t know why. So I changed the procedure #8.


2019 17" HP OMEN 17-cb0065TX (RTX2070) [9th,6C,H] + RTX 3080 @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 1909 // Vive Cosmos Elite [build link]  

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Joined: 6 years ago

@mo_oi, Thank you for sharing your nice VR + eGPU build! I'm very curious on why your Thunderbolt 3 cable is one-direction. Is it the .5m TB3 cable that comes with the Razer Core X Chroma? How was your overall gaming experience with Vive Cosmos Elite + Half Life Alyx through the RTX 2060S eGPU?


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2021 Gigabyte Z590i Vision D [11th,6C] + RTX 3060 Ti @ 32Gbps-TB4 (Gigabyte Gaming Box) + Win11 [build link]  

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Joined: 2 years ago

@itsage, thank you for reply!

Yes, it is that cable. I checked some times changing the cable direction. For the first time, eGPU weren't recognized, but today I could play Alyx for 30 minutes in the opposite direction and using the USB port in the eGPU for VR. So, I need to do more tests for confirming the situation.

Alyx ran almost smoothly, but in the high setting, micro stutter sometimes happened, so I changed to the middle setting. The default setting is low.

I found the performance test for various cards. These are the internal settings so eGPU settings caused more loss of performance. That site says "2060 super made no frame drops" but, my eGPU had some drops, I suppose (the steam VR performance monitor shows yellow status many times)




2019 17" HP OMEN 17-cb0065TX (RTX2070) [9th,6C,H] + RTX 3080 @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 1909 // Vive Cosmos Elite [build link]  

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Joined: 2 years ago

I finished Half life Alyx on this build. FPS drops while gaming rarely occurred, almost run 90Hz. One day, I got the error 43, I will report this and show how I solved this.

  • After 10 days of stable playing, While playing SkyrimVR, suddenly Vive screen went black and eGPU fans ran full speed. After that, restarting eGPU caused type43 error. I tried my MBP build and it worked one time but another tries caused 43 error on the MBP build, too. I thought of the hardware errors about eGPU or Tb3 cable. I changed the internal power cable to P3 from P4 and it worked, but after few minutes, error 43 came again. I re-plug GPU and it worked. After 3days of use, it worked flawlessly. I thought about electrification or something.
  • I bought 2m Tb3 active cable and I will try this. The performance loss is about 2%(Timespy score 7866 -> 7612 ), compared to the standard 0.5m passive Tb3 cable.
2019 17" HP OMEN 17-cb0065TX (RTX2070) [9th,6C,H] + RTX 3080 @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 1909 // Vive Cosmos Elite [build link]  

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