I am building my first CNC plasma cutter but i am having some problems with the speed of the steppers. i cant get it higher then 380 RPM.

The components i am using is a "HY-JK02-M 5-axis" breakout board. here is the manual that came with it: manual
the drivers: Picture were you can see i have set it to 400 pulses/rev and 2.84A.
PUL-, DIR- and ENBL- are connected to ground. ENBL+ to pin1. pin3 to DIR+ and pin16 to PUL+.
The steppers are also from Wantai, 57BYGH115-003B, 3 Amps.
The PSU is 24v 17a from wantai.

here are some screenshots from Mach3:
Motor setup
I also got the X axis connected now and both are set to 1800 mm/min velocity
Port setup
Motor outputs
General config
Diagnostics
Drivertest 1
Drivertest 2
Drivertest 3

I just replaced the computer that controls the drivers so it has a onboard LPT but an AGP GPU. i uninstalled every single program that was not critical for mach3 to function. i used one before with an onboard GPU but i got alot more spikes on the drivertest and the motors ran the best when i had 3 us additional pulse width, and i could only get up to 250 rpm.