Hello.  Most of the Intel processors now boast of integrated graphics right on the proccessor itself - no need for a separate graphics accelerator.
 
When building a DAW to run Sonar X-series, would it be better to use the intergrated graphics of the processor, or get a dedicated graphics card?  

There are quite a few users who manage quite well just using the onboard graphics.
 
Try it, see if it runs ok for you.
 
If it doesn't, it's cheap enough to buy a PASSIVE card (no fans )

It works fine, but I use dedicated card.

It should work, but if your system is hurting for RAM or processing power, offloading graphics processing and memory to a dedicated graphics card frees up horsepower for audio processing, in many cases by a substantial margin.
 
Be aware, however, that heavy duty graphics cards with one or more fans can add to ambient room noise.

I'm running off my chip now with zero issues.
I am getting a dedicated GPU in the near future tho bot only because I want to run 3 monitors.
 
Mike