2 sets, same price, but one is a lot faster?

CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 2133 Desktop Memory Model CMZ8GX3M2X2133C9R

CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 2133 Desktop Memory Model CMZ8GX3M2A2133C11R

see comparison here
http://www.newegg.com/Product/Produ...0006142&IsNodeId=1&name=DDR3 2133 (PC3 17000)


what am i missing here?

I'd say you're not missing anything Definitely grab the CAS 9 sticks as opposed to the CAS 11. I'm guessing they have different IC's on them, which is the reason for the latency differences.

Maybe you just caught a smart buy (price mistake). Not sure why they are priced the same since one set has faster timings.