Hello everyone !
I was lurking on this site / forum for quite some time, now I feel to share my last setup 
It's still a work in progress as I have to let the casing open to avoid PSU fan going crazy.
System specs :
Laptop :
Lenovo Legion 7i ( 2020 / 15imhg05 / 81yu / 81yu0006fr )
i7 10875H / 16GB 3200MHz / 1To + 2To NVME
dGPU : RTX 2070 MaxQ
Screens :
- main : Acer Predator XB271HUBMIPRZ (27" WQHD 165Hz IPS)
- secondary : SKILLKORP SKP_E20-27 (27" WQHD 144Hz VA)
OS :Windows 10 20H2 (19042.685)
eGPU hardware :
eGPU enclosure : Razer Core X Chroma
TB3 Cable : from Razer bundle
eGPU card : MSI GeForce RTX 3080 VENTUS 3X 10G OC
Hardware pictures :
Installation steps :
No fresh OS install, just updated to Windows 20H2
Tried each available bios and now using v2.02
Undevolted CPU (-185mv) and set internal GPU mode to discrete GPU only (bios / hardware switch)
Used DDU to clean drivers and stop auto update
Installed last NV (460.97) from device manager for internal RTX 2070
Hotlug eGPU and install drivers for RTX 3080 form device manager
Tweaked RTX 3080 : undervolted GPU set to 850mv for 1890Mhz and overclocked RAM to +584Mhz (10005MHz)
Benchmarks :
Heaven
Superposition
Timespy
Port Royal
Comments :
> I have to hotplug eGPU after windows boot to avoid BSOD "DMA drivers", didn't encouter this issue with my last build (msi prestige 15 i7-10710U GTX1650 / Core X Chroma / 2080 super)
> If I stay on hybrid mode (dGPU and iGPU online) I get a lots of stuttering. Not really an issue, NV optimus seems badly implanted on this device and battery is even better without it.
> I have to hotplug eGPU after windows boot to avoid BSOD "DMA drivers", didn't encouter this issue with my last build (msi prestige 15 i7-10710U GTX1650 / Core X Chroma / 2080 super)
I tried again to clean NV drivers through DDU and also uninstall/clean drivers for usb hub part of the enclosure. 
And no more BSOD on boot with eGPU plugged. 
Got another "DMA drivers" BSOD when i tried to connect an usb hub (for deported ports) so it seems that it's more an USB (ASMedia) drivers issue than proper eGPU one.
Any advice to solve this usb driver issue ?
Hey, I have the same Laptop and was thinking of going the razer core x chroma route, would you pick this again if you could start over? I saw on razers site it supports up to 2080ti. Nice build btw 😀
To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.
.First of, this enclosure is one of the best and supports almost all GPU.
But there still some issues if you want to use it as a docking solution.
You may encounter different problems :
- usb disconnect
- usb stuttering
- ethernet disconnect
- BSOD on cold-boot
Right now I only use it for the eGPU part and it's really frustating !
Still hoping to find drivers / software / firmware solution...
To answer you, if I had to start again I might pick up an eGPU only solution or maybe the last gigabyte 3080 gaming box.
As for the lenovo legion 7i, I have two main complaints : the impossible-to-disable RVB vomit at boot and no charging through usb type C ports !
Otherwise I love it !
Posted by: @wildfear
It's still a work in progress as I have to let the casing open to avoid PSU fan going crazy.
I changed the PSU fan as it was too loud after sometime with high GPU load.
Got an Artic F8 silent and it's perfect now.
I also removed the 12cm case fan and put a 14cm one (be quiet pure wings 2) in place of the rear panel.
Still have to figure how to make the rear face more aestetic (and replace double face tape with the right screw).