Let me save you the trouble: Do not buy the Nvidia RTX 4070. It doesn’t justify its cost. I’d not touch it with a 10-foot pole unless it was selling for half the price.
Both GPUs are top-of-the-line and provide excellent performance. Here's a lowdown on the pros & cons.
RTX 3080 is the one card to rule them all. How does it perform against the 3080 Ti and the 3090? Does it fear any Radeon card? Well, as you will find out, the Nvidia GeForce RTX 3080 is simply the best graphics card for gaming when you consider performance and price, across the board, hands down.
RTX 3080 is a powerful GPU. It’s perhaps the best or the second-best (after 3080 Ti). Managing temperatures on it can be quite the hassle with typical air cooling. Let’s see the options we have for water cooling it.
Officially, the RTX 3090 costs $800 more than the RTX 3080; nearly $300 more than the RTX 3080 Ti (which is also more available thanks to a reduced mining hashrate); and $500 more than the AMD RX 6900 XT. Does it deliver the performance worth its expensiveness? In other words, is an additional 10-12 GB of non-functional VRAM worth $800?