Just installed the update and a quick 5 min test shows that it works great. Flickering is gone and g-sync is working great. The long cable I have still doesn't work, but the short cable works great. Looking forward to trying the monster cables I have coming.

kring
... NVIDIA color settings and choose 32-bit, 10 bpc, yCbCr444, Limited.

So, I might be missing something, but isn't the signal coming from a PC in RGB, so wouldn't it make sense to use RGB Full instead of yCbCr444 Limited?

kring
HDMI cable needs to be 8K 48gbs supported or you will get issues.  Windows looks fine but stuck at 60hz, some games crap out i.e. RDR2 when maxed.  These are actually really hard to find. I went with one from Walmart - Monster 8K 15ft 48gbs platinum fiber optic HDMI for $45.00.  the generic brands on amazon & ebay are probably crap knock offs. None of the other big box stores carry any 8K cables.
 

I picked up that exact 15 foot monster cable from walmart. When I use the cable the monitor flashes like crazy when "instant game response" (which is needed for g-sync) is turned on.
 
Only thing that has worked for me so far is a cheap 6 foot non-optical cable I got from Amazon. I just ordered a $230 monoprice cable that I'll get next week.

what do you mean by "You may need to cut out a rear slot divider or it blocks airflow (some other cards needed this)" I am not really understanding?

The 65" LG CX (US) model doesn't have the firmware available via the updater for that G-Sync black flashing issue at 4K 120Hz (Chroma 4:4:4, RGB, 10 or 12 bit, it didn't matter). I don't think I want to try that beta firmware listed on Reddit since it looks to be specifically for the CX 48". OLED looks great, but the CX really doesn't like nearly all white screens and dims enough to be extremely noticeable (can't be turned off apparently). Still, even without G-Sync on at 120Hz 4K RGB 12 bit (yes I know that it's a 10 bit panel) looks sexy.
 
Now, just need that G-Sync firmware update on the CX to NOT have that flashing black screen.

Its definitely not as bright as an lcd but its much better, ensure you have the oled set 100 and turn off energy saver and use high for peak brightness. 

Straykatt
Its definitely not as bright as an lcd but its much better, ensure you have the oled set 100 and turn off energy saver and use high for peak brightness. 

Thanks! I'll make sure that is set.
 
And speak of the devil! My CX just got a 03.10.41 update and 4K 120Hz with G-Sync on doesn't flicker!

Straykatt
Its definitely not as bright as an lcd but its much better, ensure you have the oled set 100 and turn off energy saver and use high for peak brightness. 

Turning off the automatic brightness limiter helps a lot here.

https://www.youtube.com/watch?v=VMyS-muSmbE

aman4672
what do you mean by "You may need to cut out a rear slot divider or it blocks airflow (some other cards needed this)" I am not really understanding?

So on the back back of your computer where the video cards Hdmi & dispay ports are located, some cases are all single slots, but the 30XX series cards are all duel slot, So you may need to cut the back of the case to make it work for a duel Slot card. Otherwise you will have a strip of metal covering the cards rear exhaust which is not good for cooling.