difference between Raid controller on mother board and contorller card?

Question

I want to know the difference between the raid controller that is build into a motherboard, (let's say one of those high end one) compare to buying a raid controller that cost as much as the motherboard it self ($150+)

Is there a speed difference? performance difference? etc?

thanks

Answer 1

I think you have to remember that the expensive raid controllers have many more features that are geared to enterprise applications. The onboard raid controllers do not have a raid PROCESSOR or MEMORY. They use the system's resources for I/O.

A RAID card can be true "hardware raid". The more expensive the card the higher the throughput and and advanced configuration features.

Onboard raid is great for general workstation purposes.

Add-on RAID controllers are for servers and high end workstations.

Answer 2

I agree with everyone else's answers, but I had something to add.

Keep in mind that in terms of performance, the maximum throughput will be limited by the speed of the bus that a card is plugged into. The entire PCI bus - all slots - is limited to 133MB/s so you are not going to get any performace gain with a PCI card. This is why many of the higher end RAID cards use the PCI-express slots.

One advantage of a card - and this is why I have a PCI-express 1x RAID card (only $40) - is that the controller is now portable to my next computer. I tried moving some drives from an older motherboard RAID controller to my new motherboard and the RAID controller on the new board was not compatible and I couldn't see my data.

Answer 3

Unfortunately, it depends on the hardware in question. You could quite feasibly have a better on-board RAID controller than the separate card.

You need to compare the specs on each device. Generally speaking the on-board RAID is great, particularly on Dells or Compaqs.

Hope this helps.

Answer 4

To expand on joe1max's answer, "Our legal system favors mothers over fathers:" There can be any number of reasons for a mother to be single and with a child, and although sometimes it's a case of the mother being the victim of an unfortunate circumstance beyond her control, and is no reflection on her standing as a parent -- e.g. the husband abandoned the family, or died -- it is much more common, and thus easy to assume that it's the girl's own fault for being in this situation -- getting pregnant out of wedlock, or taking up with some irresponsible boob who had no intention of caring for his child. On the other hand, when the father is awarded custody, it indicates at least 2 things -- 1, that he is deemed a more suitable custodian of the child than the mother, when mothers are almost always granted custody, and, 2, he stepped up to the plate to do the right thing, taking responsibility for his child, when so many fathers don't.

Answer 5

Usually it is the level of RAID supported.

Mother board systems usually only support RAID 0 (striped - faster less reliable) or RAID 1 (mirrored - same speed halved storage fully redundant for more reliability)

The better separate controller cards will support RAID 5 (Min 3 drives striped and redundant for speed and reliability)