Western Digital Caviar Green WD10EARX vs Western Digital Caviar Green WD10EARS for Motherboard with SATA II

I am having an AS Rock G41M-VGS3 R2.0 Motherboard with SATA II and I am willing to get a new internal drives and I am having the below options:

• Western Digital Caviar Green WD10EARX
• Western Digital Caviar Green WD10EARS

I am confused between these two, so is there anyone who can help me get the best, I also wanted to know if they will work fine.

Yes they will and if they does not then you can just put a jumper on pins 5&6 and then force it to SATA II mode as far as the choice is concerned you can get Western Digital Caviar Green WD10EARS, it seems to be better. Anyways the other one will do as well.