[oneshtein]

I have no idea what "reasonably fast" means for you. It good for performance when model fit inside memory of a graphic card. Nvidia 4090 with 24Gb will be more than enough to start learning. I use gaming notebook with Nvidia 3080Ti equipped with 16Gb of videomemory.

[ranger_danger]

I have no issues with using just the CPU on smaller (<= 13b) models and it's quite fast enough for me. Even 70b models still work if you have the RAM, they're just much slower.