Raid 5

[stealthgeek]

if you want RAID5, forget using the integrated onboard controller. With 3 Raptor 10,000RPM drives, the best I could manage was 16MB/s read/write scores.

 

Yes, that is 16MB per second read and write with all 3 drives together (and about 15MB/s with 3 80GB Hitachi SATA II drives but of course the SI3114 does not support SATA II so you are stuck at SATA I transfers which don't make a whit of difference anyway).

 

compare to 3x80GB Hitachi SATA II and 3x36GB Raptor in RAID-1 and RAID-0, using RAID-5 is akin to watching latex paint slowly dry on a damp, cold day.

 

If you never listen to anyone's advice ever again after this bit of advice, at least you listened to this bit of advice: for real RAID5, you will be required to purchase a rather expensive PCI or PCI-E card that can handle such a task, but trying to use the integrated onboard SI3114 controller for RAID-5 is about as wise as sniffing muratic acid (stuff used to balance PH in swimming pools...and it will eat holes in concrete and dissolve aluminum so that should give you a pretty instant clue exactly how bright that would be)

 

my 2 pence - RAID 5 on ANY chip is useless. Sustained read speeds are OK, but any random write speeds, as you found out, are terrible. Its just the nature of RAID 5 - it has to calculate parity information and write it on the parity disk on the fly. This causes the slowdown. In terms of redundancy, RAID 5 is a cost effective solution, but I wouldnt want to use it in anything except a web server or some other application that requires little writes.

 

A good alternative would be RAID 10 - this requires a minimum of 4 drives (best with 6) however. But the benefit is, you can lose up to 2 drives and still recover your data! Plus, you get close to RAID 0 performance for writes and reads.