Help with RAM

I have dell inspiron 6400 core 2 duo laptop with installed 512MB RAM. Recently when i went for upgradation of my RAM i found that RAMs of two configuration are availables
2GB 2Rx 16 PC2 and 2Gb 2Rx 8 PC2 My question is which one is better in performance?
Thanks
Answer #1
here’s a similar topic:
memory 2r x 8 vs 2r x 16
http://forum.notebookreview.com/showthread.php?t=199001
Answer #2
the low density module is compatible with just about all pc whilst high density which is cheaper to make can have problems with some controllers