Quote from: _MT_ on September 28, 2020, 10:36:09
Quote from: vertigo on September 27, 2020, 19:55:54
It's more like just adding some more cylinders to an engine to make a car faster, at the expense of a significant decrease in gas mileage, vs fine-tuning the engine and attaching a turbocharger to get a similar speed improvement while keeping the gas mileage much closer to before. Yes, it's faster, but at the cost of much higher electricity usage and turning your computer into even more of a space heater.
Actually, a turbocharged engine is going to be less efficient than naturally aspirated engine at higher loads. The reason they can get better fuel economy is that they can be more efficient at lighter loads. Like calm driving. That's down to throttling being very inefficient compared to controlling boost of a turbocharger. At higher loads, the big problem is exhaust gas temperature (in gasoline burning engines). It's so high it can destroy a turbine. And one way to combat it is to enrich the mixture which ruins fuel economy. It's a complex topic as there are quite a few things you can do to an engine to improve efficiency (and many revolve around throttling losses). So, when you put on a turbocharger, you typically improve low load efficiency at the expense of high load efficiency. This can be very easily demonstrated in aviation engines. The designs are old and primitive, but the laws of physics haven't changed.
I was told that turbochargers actually increase fuel economy, at least compared to a N/A engine of similar power. And they typically don't even work very well at lower loads, only activating at higher RPMs. Car and Driver did some fairly extensive testing and found the turbocharged cars generally performed better than their rated mileage while N/A cars actually tended to perform worse, and AFAIK two similar cars with N/A vs turbocharge, the turbocharged car is rated with better mileage. So that would certainly seem to indicate that it does indeed offer better mileage for similar power. Then again, I'm far, far from an expert, so I very well could be mistaken in this understanding, in which case I'd appreciate if you could point me to something showing, preferably with actual testing, that it's not the case.
Either way, while maybe it wasn't the best analogy in terms of accuracy, hopefully it gets the point across, that Ampere's main reason for its improved speeds seems to be simply cranking up the wattage vs actual improvements to the card.