kevinmac wrote:I am very excited to build a Pi for retro gaming. I am currently using my laptop and plugging it into my TV to play nes, snes etc however, I notice that there is an input lag on my TV but no lag on my laptop. Will there be input lag on the Pi? Or will it be as responsive as the original console?
That all depends on how you set things up.
If using Linux (eg. Raspbian), he lag should be with in the bounds of the original console, so long as there are no unneeded processes running, the emulator in use is given a high enough priority (though not to high), and the emulator is capable of running at full speed on a Quad Core ARMv8 running at an average of 1700MIPS per core in a multitasking enviroment.
If using an emulator running on bare metal (no OS at all), and taking advantage of all 4 cores, and having a good USB stack, then there should be no problem at all up to the likes of a PlayStation 2 or equivalent.
The general rule is that you can emulate any system that has less than 1/16th processing power in total than that of the host CPU(s), on bare metal and well optimized for speed (caches on, disk access buffering, good implementation algorithms, etc), adjust a little for running in a multitasking OS.
Remember when calculating the processing power of a given console that you must include the CPU, any video processing HW, and any MCU's used for IO or other tasks.