Let me explain more here. The latency is made up of several parts:
1. Keyboard. As I know all keyboard would delay every single input to prevent double clicking. This latency is relative low.
2. USB polling rate. 125hz keyboards would give 8ms more while 1000hz keyboards give only 1ms. (PS/2 keyboards use interruption, giving nearly no latency)
3. Directsound buffer (or system sound mixer). This is the main part, since it takes about 50ms of total and could be cut off.
4. System side etc, generally this would not be the problem.
This request only involves the third part.
edited
1. Keyboard. As I know all keyboard would delay every single input to prevent double clicking. This latency is relative low.
2. USB polling rate. 125hz keyboards would give 8ms more while 1000hz keyboards give only 1ms. (PS/2 keyboards use interruption, giving nearly no latency)
3. Directsound buffer (or system sound mixer). This is the main part, since it takes about 50ms of total and could be cut off.
4. System side etc, generally this would not be the problem.
This request only involves the third part.
edited