Optimal nullDC settings

Hey, I'm trying to run nullDC on this computer. I think it's fine, as it can emulate the DS at a decent rate, but for some reason, in Sonic Adventure 2, in City Escape, when the camera shifts from showing Sonic falling to behind him as he rides down, the framerate drops. So, what are the optimal settings for nullDC so I can play games at a decent speed? Graphics is not an issue.

Specs:

Graphics Card: Mobile Intel(R) 45 Express Chipset Family
Processor: Intel(R) Core(TM)2 Duo CPU T6500 @ 2.10GHz (2 CPUs), ~2.1GHz
RAM: 2048MB
Sound Card: Speakers / Headphones (IDT High Definition Audio CODEC)
OS: Windows 7 Ultimate 32-bit

1.) make sure you have the latest version of NullDC: http://www.emudev.org/nullDC-new/

2.) NullDC is an "emulator", and emulators will always be prone to issues relating to not behaving exactly like the original hardware. Emulators for two decade old systems like the SNES, and even the Genesis, are still far from being perfect.

3.) If "1." doesn't help, buy a Dreamcast, or purchase a faster computer to compensate for the emulator code not running fast enough on your PC.