Zotac Amp Box - got a working one (Weird problem with stutter/slowdowns on external display but not laptop display)
So I RMA-ed my Zotac Amp Box with RTX 3060 Ti and got another one. This time, it worked right off the bat with no problems. My laptop is an MSI GT75 Titan.
3DMark TimeSpy graphics score on Laptop display was around 9000 on the dot (8970, 9020, etc so averaging out to 9000). Everything seems ok.
When I plugged in an external monitor the eGPU video card's HDMI port, things got weird. It has this weird stutter where randomly the screen would "freeze" for about half a second to a second. I've experienced this before on my desktop when I have a bunch of displays plugged in and cloned them and other things, but not nearly as frequently (MUCH more rare). Here, it was happening every 30 seconds. Despite that, it hit 9360 or so in 3DMark TimeSpy graphics score. It should probably have done better. One thing to note is this stuttering happened during the CPU portion of the test too. The first time it happened, it docked the CPU score by several hundred points. Upon subsequent runs, it wound up being much more rare than during the Graphics Tests.
So then I ran my laptop's internal discrete GPU (GTX 1080 Mobile) through the display connected to the eGPU's video card (hey, why not) and the result was normal/expected with no hint or trace of that weird stutter/slowdown effect.
I also noticed my CPU score in TimeSpy dropped by about 150-200 when running the eGPU through laptop display and only a little (less than 50) when running through the external monitor (once I was sure the stutter hadn't impacted the latter results).
I put the GPU in my desktop to make sure it wasn't the GPU and it's performed flawlessly in it, achieving exactly what a 3060 Ti should (11200 TimeSpy Graphics Score). And there is no stutter/slowdown when running eGPU through laptop display.
I noticed some interference noise in my headphones (connected to a separate desktop) when the eGPU was running (the card draws about 200 watts, eGPU has 450w power supply from what I've read). I haven't experienced that before no matter how many desktops/laptops I've had crowding my desk. I'm wondering if there wasn't some kind of electrical interference when running to the external monitor. Who knows?
You can see some evidence of the slowdown/stutter effect in these screenshots of 3DMark: https://imgur.com/a/rhXJ1Is
All in all, I kind of liked the thing (first time I've used an eGPU), and I'll try other GPUs and configurations to see how reliable the eGPU is. I planned on using the eGPU through laptop's own display anyway.
I put a 3080 in it. It doesn't fit in the actual enclosure, so I removed the PCB, stuck it on the 3080 and attached it to a larger power supply for safe measure. It got 12504 in 3DMark TimeSpy graphics via Laptop display. This card got around 16900 in desktops recently (originally was doing 17100 or so several months back, maybe drivers or something changed something).
It got 13915 with the external display on the 3080. It had a stutter during the CPU test where 3DMark showed a spike in CPU Freq (5.2GHz!), CPU Temp, GPU Temp, GPU Load, GPU Clock Freq and GPU Mem freq... which makes me think it's something to do with power or electrical interference which is causing the slowdowns. Which I also experience on Windows desktop on the external display. So it's not a 3D thing.
@blackbeard_, in my experience you need to go into Device Manager > Display adapters & DISABLE the mGPU as it interferes with the eGPU.
ie. My Display adapters show;
Intel UHD Graphics 630
NVIDIA GTX 1650 <—DISABLE this mGPU
NVIDIA RTX 3060 Ti (eGPU)
Once the mGPU is disabled you don’t have to do it here again in Device Manager. I tried uninstalling the mGPU as well but for some reason when I reboot Win10 just reinstalls & enables the device again.
In short, DISABLE the mGPU to avoid any conflicts when running an external monitor from eGPU.