Problems with controlling RGB LED Stripes with K8062

What i want to do:
I want to controll a RGB LED stripe with a K8062.

What the problem is:
The reaction of control commands is to slow.
And the more LED’s are shining, the slower is the reaction of the commands.
When i run a chaser light with only one LED on, the frequency can be max. 5 times per second.
When i run a chaser light with more than 20 LED’s on, the frequency can be max. 1 times per second.
When i try to flash all channels on and off, the reaction time is longer than 2 seconds.

What i tryed to solve the problem:

  1. Use another Computer - Same Problem.

  2. Use an USB HUB with external power - Same Problem.

  3. Use the Testmode of the K8062 by using a 9V Batterie - No Problem everything seems perfect. All LED’ changing simultaneously.

  4. When i use a test console from a friend to send the DMX signals, everything is ok.
    For example, you can flash all LED’s at the same time, on or off. This works perfekt until 35 times per second.

    Wich Software i use:

    I use DELPHI with the released DLL to for controlling.
    But the Problem is the same, when i use the DMX Light Player.

I need help fo solutions.