Simulations are particularly CPU intensive compared to most other game genres. When you combine that with the complexity of graphics, internet/voice connectivity, and surround sound settings, many believe that a stand alone sound card provides better sound while taking some of the burden off of the CPU. Also poor RealTek drivers used to be the cause of many games malfunctioning (this was many years ago when Soundblaster was the defacto standard) and I think that reputation still lingers some.
In my case I had built this computer in 2013 and initially was using the Realtek onboard sound chip. I got the SBAudigy card from another computer and decided to install it to see if it made any difference. I noticed no increase in performance. However, since I did not notice any decrease in performance I just left it in. Then along comes SH4 to correct the error of my ways!
