Cubase 8 high asio and bad performance

Hello forum :slight_smile:

5930k 6-core
16 gig ram
Msi X99A sli plus motherboard
Rolan Quad Capture (external soudcard, usb. 2.0)

Cubase 8 Pro
Native Komplete 10

When I start Cubase 8 the asio meter is 1/3 up and you can see a red mark at the top.
When I make music the sound goes away for very short bursts and then comes back.
The asio meter also seems to jump up and down and do not stay fixed.
I have a very powerful pc so why does it handles cubase so poorly.
I know there are a lot of experts on this forum so I wonder if you have any ide to why I have such bad performance.

Best regards