Any FPS is this but with about a million possibilities (depends on the screen resolution). People can become crazy good at it.

Before you say it does not require decisions - you can have friendly fire on.

IO is the problem not processing power.

This measures latency not processing power. You can have 10 b/s or 1 Gb/s of processing power with the same latency.

yes, but the greater the latency, the greater the number of bits per period required to get the same throughput.

I come in around 250 ms on the latency, which means that to get up to 10 bps I'd need to actually be able to discriminate between 6 choices each time.

To get up to 100 bps?