Want something faster? Look into business small PCs they are about the size of the small ps2 and will have Intel i3s to i7s. I’d just recommend looking for one that is at least the 8th gen Intel if you care about power efficiency. If using eBay search for used auctions and use a bid sniper that uses the official api

Are they still available? When I looked recently, most of it was Haswell/4th gen, and/or the seller had taken nearly all the parts out, like the memory, drives, and CPU.