The official Nvidia GeForce Twitter account has published a teaser video with the hashtag #UltimateCountdown. Unfortunately, the video is very vague; all we get to see is what appears to be an animation of something like the big bang (astrophysical concept, not sit-com). However, if you go to the Nvidia GeForce Twitter home page you will see the firm has changed the header image to the one directly below.
Above you can see that the publication of this video coincides with the #UltimateCountdown of 21 days. That takes us neatly to 31st August 2020, which marks the 21st anniversary of the announcement of the GeForce 256 (subsequently released on 11th Oct 1999). Notably, the GeForce 256 which was produced on TSMC's 220nm process, was marketed by Nvidia as the "the world's first 'GPU', or Graphics Processing Unit". The 256 in the name of this GPU refers to the "256-bit QuadPipe Rendering Engine", rather than the amount of RAM on board (32MB).
So, Nvidia is teasing a media / computing release as 'explosive' as that of the GeForce 256. However, the upcoming event is rather a known quantity, as it is going to be the platform where a series of consumer graphics cards based upon the Ampere GPU are unveiled. We've already seen Ampere GPUs for data centres and so on, and have some idea about their potential in consumer PCs for gaming and rendering.
Reading through rumours and forums, people are expecting a 30 per cent of so uplift with the new generation, but are worried about pricing by the green team.
We might see a few more informative teasers between now and 31st August. VideoCardz reckons that after the 31st August announcement the first RTX 30 series graphics cards will be launched on 9th Sept.
There is a special event countdown page and blog post now, explaining a bit more about what happens at the end of the countdown. https://www.nvidia.com/en-gb/geforce/special-event/ - "Get ready for the #UltimateCountdown, concluding 9am PT on September 1st."