CPU requirements for RAID 5/6?

[adam-the-kiwi]

If I were building a fileserver with a dedicated RAID controller card running 4 x 500GB SATA disks in a RAID 5 configuration and attaching it to GigaE, what would be the minimum CPU that I would need such that the CPU was not the bottle-neck?

What about if it were, say, 5 X 500GB SATA disks in a RAID 6?

Cheers - Adam...

 

[leo2kp]

Probably just a basic, cheap dual-core. One core should be good to calculate parity while the other can handle OS tasks. Any speed should do fine as long as you're not expecting gaming performance on this machine 😉

 

[chunkymonster]

If I were building a fileserver with a dedicated RAID controller card running 4 x 500GB SATA disks in a RAID 5 configuration and attaching it to GigaE, what would be the minimum CPU that I would need such that the CPU was not the bottle-neck?

What about if it were, say, 5 X 500GB SATA disks in a RAID 6?

Cheers - Adam...

If you use a RAID controller card that has an onboard XOR processor (3Ware, Areca, HighPoint), then the system cpu is removed from performing any parity calculations and you can get away with a low MHz single core proc. With a dedicated RAID controller card, a single core Celeron 430 1.8GHz would be more than fast enough for a file server/NAS.

 

[adam-the-kiwi]

No, I just want a configuration such that the disk IO or the gigabit network (neither of which I can reasonably do anything about) are the limiting factors. This box will be running a pared-down Linux or FreeNas (or similar) OS and nothing else.

Having said that, I want this to be as low-power as possible, so I'm looking at either dredging up a dinosaur processor or using a modern ultra-low-power (mobile) cpu. How can I work out what processing power is required to run this?

Thanks!

 

[adam-the-kiwi]

chunkymonster - thanks! That makes my life much easier...