2018 14" Lenovo ThinkPad X1 Carbon 6th Gen [8th,4C,U] + GTX Titan @ 32Gbps-TB3 (...
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Joined: 12 months ago

At first I was aiming for ADT-Link R43SG-TB3 because of the price. Besides, I'm quite a handy man and this could be a very nice project.

But, ADT-link TB3 is ~$160 + decent power supply ~$100 = I would have spent some $260 for (hopefully) working setup without any kind of enclosure, let alone additional USB or RJ-45 ports.

Used Core X (not Chroma) on Ebay are about 230-270$, so this didn't seem worth an effort building it myself.

Finally I managed to find and buy used Chroma version in top condition at this price tag.


System specs:

  • 2018 Lenovo Thinkpad X1 Carbon 6th Gen 20KH
  • Intel Core i7-8550U CPU @ 1.80GHz
  • 16 GB RAM
  • Intel UHD Graphics 620
  • HDR 2560x1440 display


eGPU hardware:


Hardware pictures:


Installation steps:

  1. Installed GPU into an enclosure, connected cables, switched on eGPU.
  2. Laptop started charging, enclosure LEDs lit up, but nothing else happened on PC side.
  3. Followed this Lenovo support article, double checked versions and reinstalled Thunderbolt software.
  4. Still nothing happens, Thunderbolt software still showing no connected device
  5. Found mention about Thunderbolt security setting in BIOS and set this.
  6. Razer device detected, GPU detected, installed Nvidia driver, everything worked from now on. More or less.


Next steps:

After each reboot Action Center notification popped up, stating "Device was approved during boot but is not part of the current Approved Devices list."

Replaced Thunderbolt Software by Thunderbolt Control Center, which allowed me to approve Razer device and set BIOS Thunderbolt security to this.

At first I was quite concerned about particular GPU model support, since Razer website states distinct set of GPUs as supported, while saying nothing about others. Fortunately found that my both cards (GTX Titan and GTX Titan Black) work just fine and even tried a small GTX 710 (which is not listed as supported) and it worked as well. 

My idea is, that Razer enclosure is just a generic PCIe extension, so there might be no reason to support one card, but not the other. Not really sure if this is true though.



Unigine superposition benchmark (1080p medium, internal display): 7166 (compare to 812 points without eGPU).

Desktop PC (i7 9700KF/16GB RAM/1TB SSD) with the same card connected internally made a score of about 7400, so the performance drop is really minimal.

Unfortunately desktop PC lacks TB3 port, otherwise it would be interesting to compare results of the same GPU connected internally and externally.



I was really excited how big difference eGPU made here and how low was the lost of performance compared to desktop PC. After some tests I found some space for improvement though:

  • at some point Superposition benchmark result dropped to about 4500 (30% decrease). I suspect some thermal issue and performance throttling on the laptop side, but can't confirm that right now. Thinkpad got quite hot on the underside, so I let it calm down for 30 minutes and test results returned to previous values
  • I went Core X Chroma way not because it's fancy RGB light, but because of USB and ethernet ports on the back. RJ-45 not tested, but wired mouse connected to the enclosure was very laggy every 5-10 seconds, even on plain Windows desktop (no game or benchmark running). This would ruin my idea about one cable laptop docking. Then I realized, that the mouse was connected to USB hub, which was connected to Chroma. With direct connection to the enclosure the problem seems to be solved. No extensive testing or long term usage though.
  • The setup is not really hot plug. At least not every time. But it might be due to my incorrect usage (might need to stop applications using the GPU first?), will have to do more tests. The fact is that from time to time reboot was needed for GPU to be detected correctly. Also eGPU connected mouse stopped working at some point and needed a reboot.

These drawbacks are rather minor, overall experience is very good for the moment.




This topic was modified 12 months ago
2018 14" Lenovo ThinkPad X1 Carbon 6th Gen [8th,4C,U] + GTX Titan @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 [build link]  

Boltoway and nando4 liked
New Member
Joined: 8 months ago

Good setup. I also had an X1C6, but the i5 version with an RX 470 with R43SG-TB3. The setup was actually plug & play, and I was really happy with that.

Unfortunately the poor i5 sweating really hard on AAA titles, sadly my favorite game, Detroit Become Human was unplayable with 100% CPU usage.

Now I am thinking about changing to i7-8650U version. Do you think it'll be enough? If you maybe have Detroit, could you please post a result from it (how well it's running, how o you feel, etc)? I think there is a Demo version on Steam too. Unfortunately I did not find any benchmarks, etc. from it.

I really like this notebook but I am hasitating a little bit because of this. But, If it's running well on i7 then I'll just go ahead and change my i5.

I played other titles like RDR2, Horizon Zero Dawn, Assassins Creed, they were playable, but the CPU was really struggling.

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


Active Member
Joined: 12 months ago

@kushwavez, I can basically confirm your observations.

I avoid playing CPU intensive titles when possible, except multiplayer with my son, when the desktop PC is occupied by him.

When I do, GPU is not an issue most of the time, but the CPU runs on high load and laptop is hot as hell.

When I was considering X1 configuration (2018 I suppose), I came across an interesting article with quite a surprising resolution. I was trying to find it now, unfortunately no avail.

The article was a review of X1 and it's available CPUs in terms of thermal management. The resolution was (hope I remember it right), that i7 CPU beats i5 on short term/peak loads. BUT, when the processor is loaded for longer time, thermal throttling steps in and i5 benchmark is BETTER under long term load.

So I would suggest to think twice before upgrading, it might not be the change for better game performance.

You might try to prove better google-fu and find the article, it was really convincing, graphs included and reasonable explanation provided.

So I was seriously thinking about ordering i5, despite of the fact that money was not the issue (employer pays 😀).


Detroit demo is available, and I might try it some time, but I'm struggling with disk space right now.


2018 14" Lenovo ThinkPad X1 Carbon 6th Gen [8th,4C,U] + GTX Titan @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 [build link]  

Eminent Member
Joined: 8 months ago

@kushwavez, probably not worth it imo as the 8650U has a 4.2Ghz all core Turbo which is ~24% faster than a 8250U's 3.4Ghz all core Turbo clocks- not really enough to make a profound difference like doubling performance. It's nice to have if you're getting 50FPS because you can then get over 60FPS but it isn't a particularly large improvement if you're running at say, only 10FPS, because then you get up to 13FPS. This is assuming you can even keep it running at max clocks with undervolting, strong fan profiles, and low ambient temps. 

I'll try the Detroit demo and see how I go with an 8 core though.


2019 15" Lenovo ThinkPad X1 Extreme Gen 2 (GTX1650) [9th,8C,H] + GTX 1080 Ti @ 32Gbps-TB3 (Razer Core X Chroma) + Win10 21H2 [build link]