RAID 5 setup and motherboard

[totom]

Hello,

I am looking at building a new pc and I am trying to choose the right motherboard for my needs.
I am looking at board with socket 939
I would like to do a HDD setup in RAID 5 but I only find 4 boards doing this. the MSI K8N Neo4 platinum the Gigabyte GA-K8N Ultra9 and the 2 Asus A8N-SLI delux and premiun.

I am surprised of the few numbers of boards being able of doing RAID 5. The RAID 5 is to me the best configuration for speed and security and it only requires 3 HDD versus the RAID 0+1.

Is there something I am missing or it is just that way.

I think I am going to go with the MSI board. What do you think ? I was going to choose the EPoX EP-9NPA+Ultra ATX but since there is no RAID 5 setup possible I guess I will have to go with the MSI...

Thank you

 

[imported_Kensai]

I prefer RAID 5 arrays with 4 drives.
The MSI is good. I love em.

 

[Peter]

If you want real good storage throughput, please don't do it in a standard 33 MHz PCI slot. You want PCI-X slots or at least a 4x PCIE slot. Else the slow bus will bottleneck your nice fast RAID to boring speed.

 

[totom]

Thanks for the reply,

Kensai, what is the advantage of RAID 5 with 4 drives versus 3 ?

Peter, what pci slot has to do with storage throughput ? Do you use your SATA ports for your HDD ? Light me up here, I am a newbie !

 

[Peter]

When you're doing RAID5 and you're not doing it on a chipset's integrated SATA channels, then you need to keep an eye on what bus the storage controller is connected on.

 

[aka1nas]

Keep in mind that RAID 5 also has relatively horrible write speed. It will not be as fast as a 0+1 array and the cost for a controller that can do it half decently will be more than buying the 4th drive and doing a 0+1 on your motherboards controller.

 

[Peter]

RAID5 write speed is perfectly OK as long as you're using an actual (hardware) RAID controller on an adequate bus. Soft-RAID5 on standard 33 MHz PCI is no fun.

 

[Jeff7]

Originally posted by: aka1nas
Keep in mind that RAID 5 also has relatively horrible write speed. It will not be as fast as a 0+1 array and the cost for a controller that can do it half decently will be more than buying the 4th drive and doing a 0+1 on your motherboards controller.

Relative to what, a 15000rpm SCSI drive? I've got a 4-drive RAID 5 setup here on a Promise SX4000 and I find it to be considerably faster than a standalone drive at any task I throw at it, which sometimes includes moving around video and audio files anywhere from 1GB to 90GB.
Unless you refer to software-based RAID 5. Then the parity calculations will hog the CPU, and then THAT will slow down the write operation. RAID 5 should only be done if you're going to have a card that can do the parity calculations itself.

It's one of those things that, if done with a dollar sign as your only guiding light, you're going to call it money wasted. If you put down the money for the good hardware, you'll love the investment.

In regards to the 33MHz PCI bus, my 4-drive RAID 5 can manage about 100MB/sec sustained, so that does only leave 33MB/sec available for the rest of the bus. The system seems to run ok though. If I had an SX6000 with 6 drives, I imagine that THAT would overwhelm a 33MHz PCI bus.