Maybe not per watt, but unless you already happen to own a 3900 cited by that post, you'd have to buy that as well, which is currently selling for around $1400 used.
I do have a 3090 Ti on my gaming PC, but even my old M1 MBP (with a mere 32gb of RAM) is quite competent and can run a quantized `Gemma4-26B-A4B` in the background while I do other stuff.
To be fair, I can also use that 3900 for other things locally. Not just AI.
3090s are running $1400 now? Wowsers. I thought I was overspending when I bought 6x of them for around $800 a pop.
Might be time to sell, to be honest. It's fun to have that at home, but I can't justify having $10k (with memory, mobo, cpu, etc) sitting in my basement without being fully utilized.