RAID 5 questions

Ben M · 13 Feb 2009 at 01:10

Would 4 of these (or the 160gb F1s, if they come in stock) in RAID 5 be good for an OS and programmes array? With it being RAID 5, the array can be rebuilt in the case of one drive failing, can it not? And the performance should be good.

Cheers.

rpstewart · 13 Feb 2009 at 08:50

Unless your willing to spend a couple of hundred on a decent RAID controller I'd give RAID5 a miss. Motherboard controllers don't have any hardware assistance for the parity calculations so they all have to be done by the CPU. This places an extra load on the PC and limits write speeds to around 30-40Mb/s which is less than half what one of those drives on its own is capable of.

RAID10 (or even RAID1 depending on your usage) will give you better performance than RAID5 from a motherboard controller.

Ben M · 13 Feb 2009 at 12:11

rpstewart said:
Unless your willing to spend a couple of hundred on a decent RAID controller I'd give RAID5 a miss. Motherboard controllers don't have any hardware assistance for the parity calculations so they all have to be done by the CPU. This places an extra load on the PC and limits write speeds to around 30-40Mb/s which is less than half what one of those drives on its own is capable of.

RAID10 (or even RAID1 depending on your usage) will give you better performance than RAID5 from a motherboard controller.

Ah okay In which case I'd probably go for 4 320gb spinpoints in RAID 10.

Cheers

Slime101 · 14 Feb 2009 at 20:19

Despite all the bad things said about RAID5 using an onboard controller ive found it to be superb. We built a server for a 8 PC network using 3 drives in raid 5 and on board controller, the CPU overhead was 5% which is nothing and write/read speeds are awsome, we never notice any problem, i rekon the 100mbit network is a bigger bottleneck than anything else.