All of it!!!
In all seriousness, I assume you mean on their development machine. These days 16GB is probably the minimum for that. 32GB is better. My workstation commonly has enough things open that it’s using 18–20GB of physical RAM at most times. I have 64GB, if you’re looking for another data point.
Now if I’m also running Virtual Machines, I’ll need at least another 8GB per VM on top of that.
In either case, disk speed is usually more important, so long as you have a reasonable amount of RAM. This is why an SSD is so important for having a fast machine.
I would like to point out that if you’re doing embedded systems development or working with micro controllers, some of those bad boys have less space than a 3.5” floppy drive.
I once worked on a robot we built using an RC Humvee as the base of the vehicle. There was a stepper motor turret where 4 distance sensors were mounted to measure distance, another stepper motor to wave the white flag if it was captured, several lights indicating distance in each direction and a few switches to reset the system. When you got too close, it would calculate the best escape route and GTFO. If you approached quickly from multiple sides and it was cornered, it would surrender.
The entire program fit into 768 bytes of RAM, which is exactly what it had available with nothing to spare. Our professor asked us to add all kinds of features & options but we kept telling him no, there wasn’t enough RAM available. He offered all kinds of optimizations, all of which we’d already implemented.
Finally, he looked at the code and realized we had already done far more than he expected or that he thought was possible. At that point he finally relented.
How much RAM do you need? Surprisingly little. But you’re always going to want more.
