So I came from a 1080ti hybrid so I was used to a fairly silent GPU, so I am not sure if this is just how blower cards are or if theres something more, but basically my 3090 FTW makes this vibrating motor noise whenever the fans get past like 50% and because my case is metal, it amplifies it a lot. Heres an example: 

In the video I am not talking about the noise of the actual air moving past the fans, but rather what sounds like the fan motors spinning up and vibrating more and more as the RPMs increase.

Is this the same for everyone's FTW 3090?

Having connection issues with 48 CX and 3080 hoping you guys can help. I previously had a gtx 1080 and everything worked fine. With the 3080 I only have 60hz available and under pc resolution 4K and 2k are not listed where they were with the 1080. Also when I try to enable deep color or game mode the tv loses signal and I have to disable and restart the tv.

I thought it may be a cable issue so I bought a new 8k cable and still have the same result. I have the latest nvidia drivers, latest LG firmware, and updated the 3080 firmware. Anybody have any ideas what could be causing this?

timc878 - I can pretty much guarantee it's the cable. that's the exact symptoms that having insufficient bandwidth in the cable will show.
 
Was it an amazon cable? all those are probably garbage. 
 
I just received this cable: Monoprice DynamicView Ultra 8K Premium High Speed HDMI Cable, 48Gbps, 8K, Dynamic HDR, eARC, 6ft Black.  Ordered direct from them for $14 shipped.
 
I had the Monster Optical HDMI and I experienced issues with that cable so it's going back, which others had similar troubles.  many games wouldn't play full screen, and RDR2 Vulkan never worked... swapped to this monoprice cable and no issues so far...  I have a feeling there are very few cables that actually support 48gbps.

Yep, definitely a cable issue. I went through tons of cables with the exact same problem before finding one that works (monoprice 30 ft 8k optical HDMI).

So I just bought a audioquest pearl 1m cable and still having the same issue. Guess I’ll keep trying cables to find one that works. I use monoprice frequently but I would like to avoid the shipping delay.

aldur80
Yep, definitely a cable issue. I went through tons of cables with the exact same problem before finding one that works (monoprice 30 ft 8k optical HDMI).

I got the 40 ft optical cable from monoprice with no luck. It wouldn't work at anything above 1080p 120 hz on my C9. Oddly enough it would work at 4k 60 8 bit if I had a 2nd monitor plugged in but got no signal with just the TV plugged in. If I use a 6 ft monoprice 2.1 cable 4k 120hz 12 bit rgb works fine.

My 3090 is arriving on Tuesday. Is the recommended settings for the LG C9 going to be RGB Full 10bit 4:4:4 with TV black level (in PC mode) set to high?

it will be: Highest, 10 bpc, RGB, Full.   there is no 4:4:4 with RGB.   you can see all the settings in the first post and other info, I keep that updated.

I have an LGCX48 with a MSI Ventus 3090 and really just wanted to say thank you to all the posts here. Definitely some frustrating setup, mostly on the LG side. Short version:

• Latest Nvidia drivers solved the crashes, and LG firmware applied
• Turning off Instant Game Response solved black flicker issues
• 10 bpc RGB full (was on the 4:4:4)
• Learning how to make your HDMI input a PC port through the home screen is crazy buried! Turning off and on the TV again fixed any resolution cropping issues during setup.

The one thing that blew me away was really how amazing 4K 120Hz gaming is. I'm not really achieving 120 fps, but definitely in the range of 90+. And OMG the cursor smoothness was not expected. I've been gimping around with a 2080 Ti which through HDMI limited me to 60Hz though the card couldn't truly push past that anyways. Whole new world! 

morness
I have an LGCX48 with a MSI Ventus 3090 and really just wanted to say thank you to all the posts here. Definitely some frustrating setup, mostly on the LG side. Short version:

• Latest Nvidia drivers solved the crashes, and LG firmware applied
• Turning off Instant Game Response solved black flicker issues
• 10 bpc RGB full (was on the 4:4:4)
• Learning how to make your HDMI input a PC port through the home screen is crazy buried! Turning off and on the TV again fixed any resolution cropping issues during setup.

The one thing that blew me away was really how amazing 4K 120Hz gaming is. I'm not really achieving 120 fps, but definitely in the range of 90+. And OMG the cursor smoothness was not expected. I've been gimping around with a 2080 Ti which through HDMI limited me to 60Hz though the card couldn't truly push past that anyways. Whole new world! 

Keep in mind that turning off "Instant Game Response" mode turns off G-sync. Although G-sync won't show that it's off in the Nvidia control panel until you start a game.
 
I was getting the same flickering issues with "Instant Game Response" mode that you were. Simply turning it off and back on every time I was about to start a game fixes it for me.