I have a problem with my S3420GP Board by using M393B5170DZ1-CF8 RAM Modules. After Installing one or two RAM Modules I get 3 beeps, which indicates an incorrect RAM Configuration. By reading the compatibilty list (http://www.intel.com/support/motherboards/server/s3420gp/sb/CS-030738.htm Intel® Server Board S3420GP — Memory and Hardware Compatibility) I found the module:SamsungM393B5170DZ1-CF84 GBRegistered1066 MHzDualK4B1G0446D-HCF8SamsungN/A1.5 Volts
I have also installed the latest BIOS Update of 2014.
Do not trust the beeps and the lights. I had the same problem with my S3420GPLX board. It says RAM error by looking up the error code. But I know the RAMs are good.
I reset the BIOS many times. A lot of errors are related to the RAID controller. But now everything works just fine, with the exact same hardware.....
Just have to keep trying....