Yeah that looks like resistive heating, so there’s no reason to think it’s more efficient than the small heater which definitely uses resistive heating. It’s impossible to know for certain but my gut says the small heater is the right call - since you’re heating a smaller area, there’s less surface area to lose heat from, and heat losses are what drives heating costs.
3dfx Voodoo 5 5500. I remember thinking it was so cool that it had 2 chips on the same board: https://en.wikipedia.org/wiki/Voodoo_5