Samsung S27A950D "Not Optimum Mode" Displayport error.

[GotNoRice]

My 27" Samsung S27A950D is having an issue where several times a day it will stop displaying what is on-screen and instead only display a "Not Optimum Mode" error instead. This only happens when connected via Displayport. Only turning the monitor off and then on again fixes it. It's definitely set at the correct resolution.

I've had this monitor for a while, as it is a pretty old monitor (~2012). Previously with my 3x GTX680 SLI setup it had this issue also. My solution years ago was to switch from using Displayport to Dual-Link DVI, after which the problems disappeared and I practically forgot it was an issue. Now I'm using an RTX2080 that only has Displayport and HDMI ports. The monitor has an HDMI port but it is a 120hz panel, and can only do 60hz via HDMI, so with the RTX2080 Displayport is my only option for 120hz.

Any ideas on why it's doing this or how I might fix this? It doesn't seem to be related to anything I'm doing on the computer, as sometimes it will do it even while I'm just browsing a web page, etc.

 

[MajorMullet]

Oh man this brings back some memories. I had the S27A750D years ago and it had the exact same issue. I was never able to find a fix for it I tried numerous display port cables at the time and it happened with all of them.

It was a great monitor other than that though, colors really looked awesome with the glossy screen.

 

[Armenius]

Does this happen when waking from sleep or randomly while you're actively using it? All the monitors I've used with DP 1.1 and 1.2 occasionally have this issue when waking from sleep, which is fixed with a power cycle. I've never had it happen while they were in active use.

 

[MajorMullet]

On my 750D it would happen during use. It was most annoying when playing games - I had a number of deaths in BF because of it

 

[GotNoRice]

Does this happen when waking from sleep or randomly while you're actively using it? All the monitors I've used with DP 1.1 and 1.2 occasionally have this issue when waking from sleep, which is fixed with a power cycle. I've never had it happen while they were in active use.

Currently it only happens randomly and always during active use. I seem to recall before that it would also happen whenever I alt-tabbed out of a full-screen game or anything that caused the screen to black out for a second. Thankfully it doesn't do that anymore. But still, having to turn the monitor off and on a few times per day at random times is pretty annoying, especially during a game.

 

[cageymaru]

I used to have that issue, then I bought an Accell cable and it fixed most of the "Not Optimum Mode" issues I believe. This seems to be the Accell cable that I ordered when digging through my Amazon history.
https://www.amazon.com/gp/product/B00CD1FB4E/

I still have the monitor, but it has new issues due to a crackhead breaking into my home and squashing it flat. He is enjoying jail in Texas from what I hear, so its all good. I might dig it out and find a use for it.

 

[Armenius]

I've been reading around and it seems that this monitor is really using DP 1.1 instead of 1.2 as advertised. 1.1 was the first version in consumer products, so it probably had quite a few issues.