There’s been rumors of this, but it’s not confirmed. A big percentage of the cost of the 3090 (and 3080) is the GDDR6X. A 3080 with 20GB of GDDR6X will still be really expensive, so it’s unclear to me that they will actually release something like that. Potentially they could put that much RAM on a card and then use slower GDDR6, but that’s kind of an odd part in Nvidia’s product offerings because then the 3080 with more RAM would be slower in a lot of situations.

There are rumors about 48GB 3090 with older GDDR6 chips so having the same config for 3080 wouldn't be unexpected, at least until Micron could produce 2GB GDDR6X chips.

what would be the benefit there? 20GB can't be that much cheaper than 24GB, right?

It will be for the gamers who think that 10 GB isn't enough VRAM, and as a way for nVidia to have an answer for rumors that AMD's next GPU will have 16 GB.

2x 20gb 3080 for $1000 each is more cost effective than 2x 3090 for $1500 each, if your model fits into 20 gb.

My guess is it’s going to be $999