Most nav programs don't need rocket ship computers. They will run on old technology just as well as on the latest stuff. So anyone who buys a new notebook for a chartplotter is wasting money.
I buy old cheap notebooks ($150 each) when I can and friends who use them in business and "need the best" give me their old ones when they upgrade. I now have five fully functional notebooks loaded with exactly the same software and all are working 100%. And I have quality charts that cover the entire planet.
So when I go cruising (hopefully not too far away) I will take at least
five notebooks (all except one will be vacuum packed) with me because they take little room to stow. When one stops working for ANY reason, it'll go in the bin and the next one will come out.
And by the way, the first one has now been functional inside my chart table with no additional cooling fans or other add-ons and has yet to miss a beat. I use a wireless keyboard and mouse so the only time the notebook is touched by human hand is when it is switched on. The display is a flat-screen built into the console and I plan on another on deck in the near future. That way the notebook lid stays closed when it's running.
To me notebooks as chart plotters are a no-brainer. There is a power issue with them but that is more easily solved that having a full range of cruising charts on a chart plotter. A spare power supply is a good idea but then most throw-away notebooks also have throw-away power supplies.