Toxickun

VRAM, the GPU's memory itself.

At it's core, it's the same issue behind the early 20xx series cards and their (somewhat common) failures.
 

Most often in my direct experience, artifacting like this is related to memory. It's not necessarily limited to instability, as failing or failed memory chip(s) can produce the same issue.

I did the same exact thing but around 2 weeks prior to you. I had no idea the 30 series was coming out right now. I returned it to Walmart, lol with all of 2 days left out of the 30 days I had to return it. With tax it was little over 1k for a 2080 Super Founders edition. Returning it was a no brainer. The 3080 is a lot better AND I'll be saving money, assuming I can get one at launch anyways. Newegg like Wally World gives you 30 days to return. Did you buy it directly from them or from one of their third party sellers? Some third party sellers like to add things like restocking fees. I'd look into returning it if you can if I was you.
 
To answer your question as to why the 20 series is so expensive, it's because things are worth what people are willing to pay. That's basic economics 101. You have to keep in mind that the prices you see right now at launch for the 30 series is just that. At launch. The current stock is going to sell out practically instantly and the prices are going to rise. Some have theorized that Nvidia is specifically limiting stock to drive up prices. I have no idea if that's true or not. It wouldn't surprise me and doing so is pretty much a no brainer business wise. But all I know is expect prices of the 30 series to rise regardless. That's why I'm going to try my hardest to get one tomorrow. When the wiser but more expensive course is to wait until all AIB cards are out with all their relevant info like bench marking and overclocking results. Personally I'd rather save money than get the best 3080 I can because no matter what I get it'll be a lot better than the 2080.
 
And BTW it wasn't seemingly out of nowhere. People like you and I simply didn't do our homework.

Your CPU will bottleneck the GPU hugely. If you're not going to build a whole new PC, I would overclock the CPU. But even then it will still bottleneck the GPU. It would bottleneck an RTX 2080, too.
 
For reference, my i7 2600k CPU overclocked is faster than your i7 4770, and it still bottlenecks my GTX 1070.
 
If you decide to overclock your CPU, you'll have to do some research to learn how to do it safely. Don't give the CPU too much voltage.

It is, but only within a single line of products (so within two RTX 3080 cards or within two 2080 Super cards, you can compare clock for clock).
When you start comparing boostclock alone within multiple cards, generations or even manufacturers you run into trouble. Clockspeed is just one variable of the performance calculation.
It would be kind of like comparing two cars based on the amount of gas you can put in a tank and the amount of cylinders it has. Definitely part of the calculation, but not the full story.
The most important thing is to look at videocards from the perspective of your workflow. That means benchmarks are usually the most valuable type of material to use when comparing videocards; because you'll realistically see how one videocard stacks up to another, in different aspects of its perfomance.

If you have time to return it, mind as well save yourself the additional 180 bucks and upgrade when possible.

The 3080 is a lot more powerful, so yeah I would probably return the 2080 if possible, and assuming you won't be losing any money. 

Reviews are out, so go check them out.
3080 is the most powerful consumer graphics card in the world right now (by a pretty large margin)
I'd return the 2080 and buy the 3080, but keep in mind that the 3080 might be out of stock for a while, so you may end up without a GPU for several weeks.

Don't compare videocards based on clockspeeds.
Base it on actual peformance in benchmarks.
The 3080 seems to be two times as fast as the 2080 AT BEST. Usually it's more like 1.5-1.7 times its performance.
We've had rumors about a September launch since August, rumors in general for longer.
The past three weeks have been nothing but people on this forum recommending people to wait out the new launches.
Watch a review or two and decide if the extra performance is worth it.
If you can return the 2080 Super and can get an RTX 3080, it's definitely worth it.

As an overall view on performance difference:

121 vs 171 fps.