Upon opening, intermittent timeline red bar for projects/sequences resulting in poor performance

I would assume that.

Except for the non gpu acc effects/assets and too many stacked effects.

Ann, are you saying with a properly functioning GPU you will never see red?

Thanks. 

I noticed when I was testing some stuff like that recently, I was seeing if my rendered timeline would keep coming back green, when I would exit PP. It did, though sometimes I noticed it would give me a few yellow spots and after a bit of time, those turned green. So, perhaps PP is thinking about it.

If your renderbar is red it means the GPU for render and playback is not working correctly.

Make sure you have the most current gpu drive installed.

(for Nvidia that would be the Studio Driver).

No GPU information and no media and effects used data. Still incomplete to make any judgment.

And the changes between red and yellow depend on what system resources are available for use versus Premiere needs at that moment. Which depending on various factors can be fluid.

Maybe you're right. I've noted the system details below.

Here's why I don't think the system details make much of a difference, though. When I say sometimes it is RED, sometimes it is YELLOW, I mean, in one session, where all I am doing is opening and closing these projects and nothing else changes, within the span of 10 minutes, I get mostly RED, and occasionally YELLOW. Seems buggy to me.

windows 10 Pro, x64
64 GB RAM (2 32gb TridentZ RGB DDR4, slots 2 and 4)
AMD Ryzen 5 3600X 6-Core Processor 3.8 GHz
ROG Strix B450-F Gaming motherboard

Samsung SSD 660 EVO 500GB (C: drive, apps)
-- 500+ gb free

Sabrent Rocket Q 8tb nvmE pdi m.2 ssd (DATA)
-- 500+ gb free

I hope this information helps.

An NLE works by metadata, right? That sequence only exists as a text file of the bits & pieces of clips used, and any effects that have been applied.

But playback is totally dependent on the complete load on the system at that specific moment. And having another app open such as a browser, can impact system resources available to Premiere. Obviously, in different amounts at different times. 

So actually, to assess your situation without a detailed knowledge of your OS, system, your media & what created it, the drives everything in the project is parked on, the available space on cache drives, all of that ... is impossible.

Clarification: "I know what red means," sounds snarky. I did not mean anything negative by it. Apologies if I offended.

I know what red means. The point is the exact same project/sequence is opened in the same way, and sometimes it shows as RED and it sometimes shows as YELLOW. YELLOW, all is fine; RED, performance is bad. Because it is sometimes fine (YELLOW) it leads me to think that when it is RED, there is an intermittent issue and it seems like that issue is a bug.

What the rest of my media/hardware is doesn't seem to be germane, because if I was underpowered in any way, I would never have good performance (YELLOW).

I'm not sure what you are asking. If it's red, it is saying, there may be dropped frames and slower performance in playback.

Of course you can render the sequence or an in to out section which would turn it green and you'd be good to go, possiby to the next edit.

What kind of media, what's your hardware like?