Max Number of Sata Drives

Hi not strictly a suse amd64 question, but i'm hoping someone on this list will be able to answer. Is the number of sata devices (and cards) stackable. I.e I have an onboard controller which supports 2 channel, can I then go and add another 4 channel sata controller card and use them all at the same time (i.e the as a striped 0 array onboard, + raid array on the 4 port card). Is there a limit to this setup, can I have say 2 4 port cards with a total of 10 drives (raided or not). Kind regards Joel W