RAID controllers on motherboards

[igorb]

I have been using MSI BX Master motherboard for the last three years and I’m very pleased
with the stability this board offers. The only feature I missed on that board is RAID 0 or
RAID 1. Soon I will upgrade my machine and I also need a new motherboard. I’m convinced that
Asus A7V333 RAID or MSI KT3 Ultra-ARU boards will suit my needs best. They both use the same
RAID controller (Promise 20276). Regarding this controller I need some additional info:

1) I would like to connect 4 disks to this RAID. Both master disks should work in RAID 0
setup and slave disk as independent disks. Can slave ports work as normal IDE controllers,
independently of RAID setup?
2) Both disks used in RAID 0 setup are ATA133 and both slave disks are ATA66. Is this going
to influence the RAID 0 performance somehow?
3) How reliable is this setup? How often such RAID setups break? I’m using w2k, any driver issues?
4) Is it possible to connect 4 discs that all of them operate independently from each other?
I would like to know if 20276 controller works in a way that all ports operate as normal ATA ports.
5) What is the difference in performance between on-board RAID solutions and RAID controllers
on PCI cards (Promise Ultra 133 TX2)?
6) Beside both disks in RAID 0 setup, I will use only one slave disk most of the time. The
secondary slave disk will be removable. Do I have to use both slave disks, or can I use only
one slave disk?
7) Can both master disks work in RAID 1 and both slave disks in RAID 0 setup? From the manual
of Asus 7V333 board I can conclude that this is not possible? Am I right? Is the same true for
HPT controllers?

From the information I find on net, I can conclude that HPT controllers are more reliable than Promise?
What is your experience? Are there any differences in disk configurations between HPT and Promise
controllers? What is that one is offering and the other doesn’t have it? What is best from the
reliability perspective? To use motherboard with onboard RAID controller or to use plain motherboard
and a decent PCI RAID controller card, like Rocket Raid 404?

 

[jlanka]

I'll take a stab at this one:

Can slave ports work as normal IDE controllers,
independently of RAID setup?

My guess would be yes, although you probably have to create a RAID array for each disk so that the controller will serve it to the OS.

Both disks used in RAID 0 setup are ATA133 and both slave disks are ATA66. Is this going
to influence the RAID 0 performance somehow?

Yes. It will hurt the performance.

How reliable is this setup? How often such RAID setups break? I’m using w2k, any driver issues?

I would keep the ATA66 slaves off the RAID controller. Put them on IDE1 and 2. I've not known the RAID controllers to fail. W2K drivers are a non-issue. Make sure to back up your important data files, a policy which should be in effect regardless if using RAID or not.

Is it possible to connect 4 discs that all of them operate independently from each other?
I would like to know if 20276 controller works in a way that all ports operate as normal ATA ports.

Yes, there should be a jumper somewhere to switch to normal IDE controller mode.

What is the difference in performance between on-board RAID solutions and RAID controllers
on PCI cards (Promise Ultra 133 TX2)?

negligable.

Beside both disks in RAID 0 setup, I will use only one slave disk most of the time. The
secondary slave disk will be removable. Do I have to use both slave disks, or can I use only
one slave disk?

one is fine.

Can both master disks work in RAID 1 and both slave disks in RAID 0 setup? From the manual
of Asus 7V333 board I can conclude that this is not possible? Am I right? Is the same true for
HPT controllers?

My inclination would be that it is possible, but since you read the manual...

I've used both brands, and haven't found much difference between the 2. I'd pick the motherboard/chipset you want as the 1st consideration. If you're very concerned about the RAID controller, then an add on card sounds like the right choice for you.

As always, these are my opinions only. YMMV. Good luck.

<i>It's always the one thing you never suspected.</i>