In case other people are looking.

We were having problems finding details for this CPU. It didn't seem to be listed as part of the Athlon II X2 range of CPUs.

It seem that if single core Sempron 130 C3 has a core unlocked then (some?) BIOS start to identify this chip as a AMD Athlon II X2 4300e.

Also if a Sempron 140 is unlocked then you have a Athlon II X2 4400e.