Have the two 2GB Rigel installed and it runs perfectly!
My board has an Intel chipset (Gigabyte GA-P35-DS3).
With my previous Rigeln I now 6GB RAM. Everything works well, although the other two are from another manufacturer.
The best make sure that you paired ordered the Rigel and then always fit on the board the same color slots in pairs in order to remain in Dual Channel mode.
Windows Experience Index has now with verbesser in Pukto RAM at from 5.5 to 6.8!