If you ever need to record virtual instruments on a laptop, but you don't need to record audio using an external soundcard, you can try installing the asio4all driver.
It may help when mixing and using virtual instruments on-the-go.
I usually set my buffer length to 256 samples and monitor using my computers headphone jack.
I have had mixed results with the driver. My older laptop worked great, but the driver was very unstable on my desktop computer.