I mostly use my 2006 laptop which runs it pretty well. But the other PC I run Sins on is a Dell GX270 with the 82865G chipset. It runs sins pretty well but there are a couple of glitches.
1.) Planets, except astroids, don't look right. The planet is translucent. So it looks like a colored cloud you can see through.
2.) The ships look fine but lack the reflection quality and the team color is never rendered.
Other than that it looks fine. In Effects settings I turn off everything but "colored sky boxes" set planets to low detail, and ship and building detail is high. I set Bump and Extras at low. These settings save LOTS of memory usage.